YIELD AND YIELD COMPONENTS ON SOME WHEAT VARIETIES GROWN IN ALEKSINAC REGION

Yield and yield components of 5 wheat varieties (Kruna, Toplica, Zvezdana, Etida, Angelina) in Aleksinac region (Serbia) were analysed. The experiment was performed in randomized block design in 3 replications on the experimental field in area of Aleksinac city. The results showed relatively high yields in all varieties. The general average yield was 6140 kg ha-1. The highest average yield varied from 6858 kg ha-1 in cultivar Zvezdana to 5050 kg ha-1 in Toplica. The cultivar Kruna showed lowest number of productive stems per square meter – 572, and largest number in Zvezdana and Angelina, with an average of 658 and 641, respectively. Average longest spike was found in variety Angelina 12.4 cm, and shortest in Toplica (9.8 cm). The average number of spikelets per spike for all cultivars was 19.4. Cultivar Angelina showed biggest number (21.1), and Kruna smallest number (17.9). The biggest number of grains per spike was obtained in cultivar Etida (54.8), and lowest in Zvezdana (51.4). During the examination, the highest average value for hectoliter weight is obtained in variety Zvezdana (78.3 kg hl-1), and lowest in Toplica (75.4 kg hl-1). From the data on yield and yield components, it can be concluded that all tested varieties can be grown in the region of Aleksinac, with preference to varieties Zvezdana and Etida

Solving advection equations by applying the crank-nicolson scheme combined with the richardson extrapolation

Advection equations appear often in large-scale mathematical models arising in many fields of science and engineering. The Crank-Nicolson scheme can successfully be used in the numerical treatment of such equations. The accuracy of the numerical solution can sometimes be increased substantially by applying the Richardson Extrapolation. Two theorems related to the accuracy of the calculations will be formulated and proved in this paper. The usefulness of the combination consisting of the Crank-Nicolson scheme and the Richardson Extrapolation will be illustrated by numerical examples. Copyright Zahari Zlatev et al

Parallel Computations with Large-scale Air Pollution Models

Large-scale mathematical models are very powerful tools in the efforts to provide more information and more detailed information about the pollution levels, especially about pollution levels which exceed certain critical values.. However, the model used must satisfy at least two conditions: (i) it must be verified that the model results are reliable and (ii) it should be possible to carry out different study by using the model. It is clear that comprehensive studies about relationships between different input parameters and the model results can only be carried out (a) if the numerical methods used in the model are sufficiently fast and (b) if the code runs efficiently on the available high-speed computers. Some results obtained recently by a new unified version of the Danish Eulerian Model will be presented in this paper.Великомасштабні математичні моделі – дуже потужний інструмент для одержання більш детальної інформації щодо рівнів забруднень. Проте використовувана модель повинна задовольнити принаймні двом умовам: (i) результати моделювання повинні бути надійними і (ii) повинна існувати можливість уточнення і вивчення різноманітних характеристик моделей. Всебічне вивчення відношень між різноманітними параметрами входу і результатами моделювання може бути виконане, якщо (a) чисельні методи, використовувані в моделі, достатньо швидкі та (b) програмне забезпечення на доступних швидкодіючих комп'ютерах достатньо ефективне. Подані результати рівнобіжної реалізації моделювання забруднення атмосфери, отримані в новій об'єднаній версії датської Ейлерової моделі.Крупномасштабные математические модели – очень мощный инструмент для получения более детальной информации относительно уровней загрязнений. Однако модель должна удовлетво- рить по крайней мере двум условиям: (i) результаты моделирования должны быть надежными и (ii) должна существовать возможность уточнения и изучения характеристик модели. Всестороннее изучение отношений между различными параметрами входа и результатами моделирования может быть выполнено, если (a) численные методы, используемые в модели, достаточно быстры и (b) программное обеспечение на доступных быстродействующих компь- ютерах достаточно эффективно. Представлены результаты параллельной реализации моделирования загрязнения атмосферы, полученные в новой объединенной версии датской Эйлеровой модели

On design and tribological behaviour of laser textured surfaces

The paper reports an investigation into the functional response of textured surfaces with different designs that incorporated arrays of micro-dimples and grooves (40 μm diameter/width and 15 μm depth for both patterns) produced on tungsten carbide (WC) blocks by employing nanosecond (ns) and femtosecond (fs) lasers. In particular, the tribological performance of the textured WC blocks against stainless steel (SS316L) counterbody was evaluated in terms of friction and wear under dry condition compared to an untextured specimen. Friction tests were carried out on a reciprocating sliding tester while unidirectional ball-on-disc method was utilised to assess wear on the mating surfaces. The untextured surface exhibited a continuous rise in the friction coefficient from 0.15 to 0.5 from the start of the cycle to the end while the specimens textured with ns and fs lasers reached steady-state condition after 100 and 200 cycles with values between 0.35-0.45 and 0.3-0.4, respectively. Energy dispersive spectroscopy following wear tests showed a pronounced material transfer from the balls to the textured surfaces with stainless steel filling up some of the dimple and groove cavities; however, the reverse phenomenon was not apparent. Additionally, texturing with the fs laser exhibited formation of nano-ripples/structures in the produced dimples and grooves that can be further studied for creating nano-textured cutting tools or surfaces with super-hydrophobic/anti-ice properties

Laser polishing of 3D printed mesoscale components

Laser polishing of various engineered materials such as glass, silica, steel, nickel and titanium alloys, has attracted considerable interest in the last 20 years due to its superior flexibility, operating speed and capability for localised surface treatment compared to conventional mechanical based methods. The paper initially reports results from process optimisation experiments aimed at investigating the influence of laser fluence and pulse overlap parameters on resulting workpiece surface roughness following laser polishing of planar 3D printed stainless steel (SS316L) specimens. A maximum reduction in roughness of over 94% (from ∼3.8 to ∼0.2 μm Sa) was achieved at the optimised settings (fluence of 9 J/cm2 and overlap factors of 95% and 88–91% along beam scanning and step-over directions respectively). Subsequent analysis using both X-ray photoelectron spectroscopy (XPS) and glow discharge optical emission spectroscopy (GDOES) confirmed the presence of surface oxide layers (predominantly consisting of Fe and Cr phases) up to a depth of ∼0.5 μm when laser polishing was performed under normal atmospheric conditions. Conversely, formation of oxide layers was negligible when operating in an inert argon gas environment. The microhardness of the polished specimens was primarily influenced by the input thermal energy, with greater sub-surface hardness (up to ∼60%) recorded in the samples processed with higher energy density. Additionally, all of the polished surfaces were free of the scratch marks, pits, holes, lumps and irregularities that were prevalent on the as-received stainless steel samples. The optimised laser polishing technology was consequently implemented for serial finishing of structured 3D printed mesoscale SS316L components. This led to substantial reductions in areal Sa and St parameters by 75% (0.489–0.126 μm) and 90% (17.71–1.21 μm) respectively, without compromising the geometrical accuracy of the native 3D printed samples

Expression of LIM kinase 1 is associated with reversible G1/S phase arrest, chromosomal instability and prostate cancer

<p>Abstract</p> <p>Background</p> <p>LIM kinase 1 (LIMK1), a LIM domain containing serine/threonine kinase, modulates actin dynamics through inactivation of the actin depolymerizing protein cofilin. Recent studies have indicated an important role of LIMK1 in growth and invasion of prostate and breast cancer cells; however, the molecular mechanism whereby LIMK1 induces tumor progression is unknown. In this study, we investigated the effects of ectopic expression of LIMK1 on cellular morphology, cell cycle progression and expression profile of LIMK1 in prostate tumors.</p> <p>Results</p> <p>Ectopic expression of LIMK1 in benign prostatic hyperplasia cells (BPH), which naturally express low levels of LIMK1, resulted in appearance of abnormal mitotic spindles, multiple centrosomes and smaller chromosomal masses. Furthermore, a transient G1/S phase arrest and delayed G2/M progression was observed in BPH cells expressing LIMK1. When treated with chemotherapeutic agent Taxol, no metaphase arrest was noted in these cells. We have also noted increased nuclear staining of LIMK1 in tumors with higher Gleason Scores and incidence of metastasis.</p> <p>Conclusion</p> <p>Our results show that increased expression of LIMK1 results in chromosomal abnormalities, aberrant cell cycle progression and alteration of normal cellular response to microtubule stabilizing agent Taxol; and that LIMK1 expression may be associated with cancerous phenotype of the prostate.</p

An Overview of Recent Strategies in Pathogen Sensing

Pathogenic bacteria are one of the major concerns in food industries and water treatment facilities because of their rapid growth and deleterious effects on human health. The development of fast and accurate detection and identification systems for bacterial strains has long been an important issue to researchers. Although confirmative for the identification of bacteria, conventional methods require time-consuming process involving either the test of characteristic metabolites or cellular reproductive cycles. In this paper, we review recent sensing strategies based on micro- and nano-fabrication technology. These technologies allow for a great improvement of detection limit, therefore, reduce the time required for sample preparation. The paper will be focused on newly developed nano- and micro-scaled biosensors, novel sensing modalities utilizing microfluidic lab-on-a-chip, and array technology for the detection of pathogenic bacteria

Understanding how immigrant entrepreneurs view business opportunity formation through ethnicity

Given that international research is now consistently showing higher rates of entrepreneurial activity from immigrants above native people, research regarding our understanding of how immigrant entrepreneurs view business opportunity formation remains underdeveloped. Based upon a review of the literature, this chapter examines how ethnicity relates to business opportunity formation through constant interactions. It also introduces the Visual Mixed Embeddedness Framework as an empirical lens for understanding the differences in the business opportunity formation process models between immigrant and native entrepreneurs. By explaining how factors and traits from both home and host countries impact upon the immigrant entrepreneurial business activity process, the framework clearly identifies how the concept of ethnicity influences immigrant entrepreneurial opportunity formation activities in different ways. The framework contributes to existing knowledge by offering a novel method for examining the influence on business opportunity formation of ethnicity, the role of home and host countries and variations between immigrant and native entrepreneurs

Unlocking the potential of weberite-type metal fluorides in electrochemical energy storage

Sodium-ion batteries (NIBs) are a front-runner among the alternative battery technologies suggested for substituting the state-of-the-art lithium-ion batteries (LIBs). The specific energy of Na-ion batteries is significantly lower than that of LIBs, which is mainly due to the lower operating potentials and higher molecular weight of sodium insertion cathode materials. To compete with the high energy density of LIBs, high voltage cathode materials are required for NIBs. Here we report a theoretical investigation on weberite-type sodium metal fluorides (SMFs), a new class of high voltage and high energy density materials which are so far unexplored as cathode materials for NIBs. The weberite structure type is highly favorable for sodium-containing transition metal fluorides, with a large variety of transition metal combinations (M, M’) adopting the corresponding Na2MM’F7 structure. A series of known and hypothetical compounds with weberite-type structure were computationally investigated to evaluate their potential as cathode materials for NIBs. Weberite-type SMFs show two-dimensional pathways for Na+ diffusion with surprisingly low activation barriers. The high energy density combined with low diffusion barriers for Na+ makes this type of compounds promising candidates for cathode materials in NIBs

Corporate Entrepreneurship:From Structures to Mindset

Corporate entrepreneurship dispersed throughout an organization and leveraging the entrepreneurial potential of all its employees bears significant benefits for those organizations that embrace it. However, it appears more difficult to instill and requires strong investment in the development of human capital and entrepreneurial mindset among the employees and across the organization. In this chapter, we discuss the essence of corporate entrepreneurship mindset and show that across an organization, there might be different entrepreneurial mindsets that correspond to different people, opportunities, and contexts. Although different, they all lead to enactment of entrepreneurial projects. This chapter, thus, contributes to the discussion regarding the nature of corporate entrepreneurial mindsets, and their development and stimulation within an organization, from both academic and practical view