PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 12

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available Characterization of Bonded Zone and Evaluation of Cracking in Vacuum Brazed Zircaloy-4 and Stainless Steel-316L Joint
Munis A., Zheng Maosheng, Akhter J. I., Ahmad M.
Archives of Metallurgy and Materials
|
2019
|
Vol. 64, iss. 2
707--713
EN
Brazing of two dissimilar structural materials; Zircaloy-4 and SS-316L was performed at 900°C under high vacuum conditions. The metallic glass ribbons (Zr55Cu30Al10Ni2Fe3-at.%) of 30 μm thickness, were used as an interlayer. The bonded region was characterized by scanning electron microscope (SEM), energy dispersive spectroscope (EDS) and microhardness testing. The metallurgical bond formation was due to compositional changes in the molten interlayer and later on its subsequent solidification. Assessment of the bonded zone (BZ) revealed three distinct regions (Region-I, Region-II and Region-III). Diffusion transformation was observed in Region-I and Region-III which were interface with base alloys SS-316L and Zircaloy-4 respectively. However, Region-II at the middle of the BZ was composed of isothermally and athermally solidified portions. The highest values of Microhardness were observed in Region-III which was due to the presence of hard phases. Moreover, a crack parallel to BZ was observed in Region-III and was attributed to differential contraction of base alloys during cooling. Maximum shear stress acting on the BZ was calculated and correlated to the brittle phase cracking.
2
Content available Carbon emissions, energy use, gross domestic product and total population in China
Ahmad M., Hengyi H., Rahman Z. U., Khan Z. U., Khan S., Khan Z.
Ekonomia i Środowisko
|
2018
|
nr 2
32--44
EN
The current study explores the impact of energy consumption, total population, gross domestic product on carbon emissions by utilizing time series data of 1971-2013 for China. Earlier studies concentrated on testing the present form of an environmental Kuznets curve not taking total population in a model. Specifically, this study focuses on analyzing the long run existence of environmental Kuznets curve. The methodology of auto regressive distributed lag model is utilized. The quadratic linkage between national income and emissions of carbon have been detected, confirming the presence of long run linkage between quadratic national income and emissions of carbon. Granger causality test divulge one-way causality between gross domestic product and carbon emissions. The empirical findings also reveal that the energy use and national income are important factors of carbon emanations in the long run. Total population has an insignificant positive influence on emissions of carbon. It is suggested that government should focus to extract that substitute sources of energy which is more environmental friendly.
3
Content available Dominant factors affecting the behavior of innovative employees
Fauzia S., Budiningsih I., Djaelani A., Ahmad M.
Polish Journal of Management Studies
|
2017
|
Vol. 16, No. 1
32--40
EN
The aim of the studies is to determine the model of the relationship between innovative employee behavior with learning organization, knowledge sharing, and organizational commitment. The method of the research is survey in 166 employees selected randomly at Multicentral Aryaguna Company - Jakarta, and analyzed by using descriptive, correlation and regression. The study fine that learning organization, knowledge sharing and organizational commitment collectively contribute to enhancinginnovative employee behavior in 62% and 38% of other factors, its mean learning organization, knowledge sharing, and organizational commitment cannot be ignored’ as an instrument to improve innovative employee behavior.
PL
Celem badań jest określenie modelu relacji pomiędzy innowacyjnymi zachowaniami pracowników, a organizacją uczącą się i dzieleniem się wiedzą. Badanie wykazało, że organizacja ucząca się, dzielenie się wiedzą oraz zaangażowanie organizacyjne wspólnie przyczyniają się do zwiększenia innowacyjnych zachowań pracowników w 62% i 38% innych czynników, co oznacza, że organizacja ucząca się, dzielenie się wiedzą i zaangażowanie organizacyjne, jako instrumenty poprawy innowacyjnego zachowania pracownika, nie mogą być ignorowane. Metodą badań była ankieta przeprowadzona wśród 166 wybranych losowo pracowników przedsiębiorstwa Multicentral Aryaguna w Dżakarcie i przeanalizowana za pomocą opisu, korelacji i regresji.
4
Content available Wykorzystanie odpadowych popiołów lotnych do wytwarzania betonu jako element budownictwa zrównoważonego
Ahmad M.
Budownictwo o Zoptymalizowanym Potencjale Energetycznym
|
2017
|
nr 2(20)
67--74
PL
W artykule przedstawiono wyniki badań laboratoryjnych wpływu dodatku mineralnego popiołu lotnego krzemionkowego na właściwości betonu. Popiół lotny został zastosowany jako zamiennik spoiwa cementowego w mieszankach betonowych ze względu na swoje właściwości pucolanowe. Do badania zaprojektowano 5 mieszanek betonowych: w jednej beton kontrolny bez dodatku popiołu lotnego, zaś w pozostałych współczynnik k (popiół lotny/cement) wynosił: 0,05; 0,11; 0,18; 0,25. Jako spoiwo cementowe zastosowany został cement portlandzki CEM I 42,5 R. Wyniki przeprowadzonych badań laboratoryjnych wykazały przydatność popiołów lotnych jako zamiennika cementu w mieszankach betonowych.
EN
In the article the results of laboratory research on influence of addition of mineral siliceous fly ash on concrete’s properties were presented. Fly ash has been used as a substitute of cement binder in concrete compounds because of it’s Pozzolanic properties. For research 5 cement compounds were designed: in one control concrete without the addition of fly ash, in the rest the k factor (fly ash/cement) stood at: 0,05; 0,11; 0,18; 0,25. As a cement binder, Portland cement CEM I 42,5 R was used. The results of the laboratory tests have shown the usefulness of fly ash as a substitute for cement in concrete mixes.
5
Content available Effect of plasticizers, superplasticizers and silica fly ash on concrete water-resistance
Ahmad M.
Challenges of Modern Technology
|
2016
|
Vol. 7, no. 3
33--38
EN
Concrete is one of the basic construction materials. It is a composite made of cement, water, coarse and fine aggregate. In the past, concrete was produced only with primary components, and it was often of poor quality. Nowadays, technological progress and scientific research allowed the concrete to be made with the use of chemical admixtures and mineral additives to modify and improve selected properties of both the concrete mixture and hardened concrete. Contrary to popular belief, obtaining concrete with suitable properties is not simple and the choice of mixture components requires professional knowledge. The care and quality is also extremely important. The paper presents the results of laboratory research concerning the impact of the plasticizer admixture—Betocrete-C17 and superplasticizer—Arpoment-O and mineral additive of silica fly ash on concrete water resistance. Capillarity, water permeability and water absorption of the concrete were determined. Additionally, a study of the consistency of fresh mixture was done and the hardened concrete compressive strength was tested.
6
Content available remote An adaptive level dependent wavelet thresholding for ECG denoising
Awal M. A., Mostafa S. S., Ahmad M., Rashid M. A.
Biocybernetics and Biomedical Engineering
|
2014
|
Vol. 34, no. 4
238--249
EN
This paper describes the research carried out to eliminate the noise found in ECG signal and cardiac rhythm. For this, ECG signals were collected carefully from BIOPAC data acquisition system and MIT-BIH database. MIT-BIH noise stress test database was used for generating realistic noises. In addition, to get a better denoised ECG, Symlet wavelet was chosen because its scaling function is closely related to the shape of ECG. For denoising ECG signal, a novel modified S-median thresholding technique is proposed and evaluated in this paper. The optimal Symlet wavelet of order 6 and decomposition level of 8 are attained for modified S-median thresholding technique. The evaluation results showed that the proposed system performed better than S-median and other existing techniques in the time domain. The frequency domain analysis also showed the preservation of important phenomena of ECG. The scalogram difference of 0.004% indicates the well preservation of time–frequency information.
7
Content available remote On semi-invariant submanifolds of a nearly trans-Sasakian manifold admitting a semi-symmetric semi-metric connection
Das L. S., Ahmad M., Danish Siddiqi M., Haseeb A.
Demonstratio Mathematica
|
2013
|
Vol. 46, nr 2
345--359
EN
We define a semi-symmetric semi-metric connection in a nearly trans-Sasakian manifold and we consider semi-invariant submanifolds of a nearly trans-Sasakian manifold endowed with a semi-symmetric semi-metric connection. Moreover, we also obtain integrability conditions of the distributions on semi-invariant submanifolds.
8
Content available remote Badania możliwości otrzymania betonów zwykłych na kruszywach recyklingowych
Ahmad M.
Zeszyty Naukowe Politechniki Rzeszowskiej. Budownictwo i Inżynieria Środowiska
|
2012
|
z. 59, nr 2/II/I
27-38
PL
Kruszywa recyklingowe uważane są za bardzo dobry substytut kruszyw naturalnych. Wykorzystywane są jako kruszywa do wytwarzania betonów niskich klas wytrzymałościowych. Do najważniejszych cech ograniczających wykorzystanie tych kruszyw w budownictwie należą: mała szczelność, niska mrozoodporność, skurcz, duża nasiąkliwość i mała wytrzymałość. W referacie przedstawione są wyniki przeprowadzonych badań laboratoryjnych wybranych właściwości mieszanki betonowej i stwardniałego betonu, wytwarzanych na bazie uszlachetnionych kruszyw recyklingowych. Uzyskane wyniki badań dowodzą, że uszlachetnione kruszywa recyklingowe mogą być stosowane jako pełnowartościowe kruszywa do produkcji betonów konstrukcyjnych wyższych klas wytrzymałościowych.
EN
Recycling aggregates are claimed to be very good substitute for natural aggregates. They are used as aggregates to produce low durability class concretes. The most important features limiting the use of these aggregates in building industry are: low tightness, low frost resistance, contraction, high absorbability and low durability. The paper presents the results of laboratory researches of selected features of concrete mixture and hardened concrete, produced on the basis of improved recycling aggregates. The results prove that improved recycling aggregates can be used as full-value aggregates to produce construction concretes of higher strength classes.
9
On semi-invariant submanifolds of a nearly Sasakian manifold admitting a semi-symmetric non-metric connection
Das L., Ahmad M., Haseeb A.
Journal of Applied Analysis
|
2011
|
Vol. 17, nr 1
119-130
EN
We define a semi-symmetric non-metric connection in a nearly Sasakian manifold and we consider semi-invariant submanifolds of a nearly Sasakian manifold endowed with a semi-symmetric non-metric connection. Moreover, we also obtain integrability conditions of the distributions on semi-invariant submanifolds.
10
Content available remote Wiener-Hopf analysis of diffraction of acoustic waves by a soft/hard half-plane
Ayub M., Mann A. B., Ahmad M., Tiwana M. H.
Archives of Mechanics
|
2010
|
Vol. 62, nr 2
157-174
EN
In this paper, firstly, the far field due to a line source scattering of acoustic waves by a soft/hard half-plane is investigated. It is observed that if the line source is shifted to a large distance, the results differ from those of [16] by a multiplicative factor. Subsequently, the scattering due to a point source is also examined using the results of line source excitation. Both the problems are solved using the Wiener–Hopf technique and the steepest descent method. Some graphs showing the effects of various parameters on the diffracted field produced by the line source incidence are also plotted.
11
Content available remote The influence of artificial resins on water resistance of gypsum materials
Ahmad M.
Zeszyty Naukowe Politechniki Rzeszowskiej. Budownictwo i Inżynieria Środowiska
|
2009
|
z. 53 [265]
5-14
EN
The thesis presents the results of laboratory research concerning the influence of combined silicon and epoxy resin supplements on hydrophobic and water resistance features of gypsum materials. For comparative reasons, the first stage concerns the influence of singular modifying preparations. It has been proved that both silicon and epoxy resins introduced to gypsum compositions separately have advantageous influence on hydrophobic and water resistance features of modified gypsum materials. However, they do not protect these materials against destructive water effects. The second stage of the research concerned introducing two preparations that have different modifying characteristics simultaneously. The results prove that this research direction is justified and it allows to obtain gypsum materials with increased hydrophobic and water resistance features, which can be used in higher humidity places.
12
Content available remote Determination of atenolol in pure substance and pharmaceutical preparations applying first order derivative spectrophotometry
Khan I. U., Yaqoob N., Ahmad M.
Chemia Analityczna
|
2005
|
Vol. 50, No. 5
951-955
EN
The improved first order derivative spectrophotometric method for the determination of atenolol in pure substance and pharmaceutical preparations has been proposed. The first order derivative spectrum of the coloured complex of atenolol with phenolsulfothaline exhibited maximum absorbance at 558.4 nm. The proposed approach allowed one to eliminate spectral interferences. The measured analytical signal changed linearly within the analyte concentration range: from 0.05 to 0.4 mg mL-1. Coefficient of variation was 0.854%. Detection limit was found to be 0.05 mg mL-1.
PL
Zaproponowano ulepszoną metodę spektrofotometrii pochodnej do oznaczania atenololu w substancji farmaceutycznej i w postaci leku. Pierwsza pochodna widma barwnego kompleksu atenololu 7. fenolosulfotalinąwykazaia maksimum absopcji przy 558,4 nm. Proponowana metoda pozwala na wyeliminowanie interferencji spektralnych. Sygnał analityczny miał liniowy przebieg w zakresie stężeń od 0,05 do 0,4 mg L-1. Współczynnik zmienności wynosił 0,854%. Granicę wykrywalności określono na 0,05 mg L-1.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.