Wyniki wyszukiwania - Biblioteka Nauki

1

A comparative effect of IAA and 4-Cl-IAA on growth, nodulation and nitrogen fixation in Vigna radiata (L.) Wilczek

100%

Ali B. , Hayat S. , Aiman Hasan S. , Ahmad A.

Acta Physiologiae Plantarum

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2008

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tom 30

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nr 1

EN

The plants of mung bean (Vigna radiata L. Wilczek) were raised from the seeds soaked in water (control), IAA or 4-C-IAA (10⁻⁶, 10⁻⁸ or 10⁻¹⁰ M) for 8 or 12 h. The plants were allowed to grow in a net house and were sampled at 30 and 45 days after sowing (DAS). Both IAA and 4-Cl-IAA significantly affected the growth (length, fresh and dry mass of roots and shoots), the number of nodules, their fresh and dry mass and the activity of nitrogenase. However, the contents of nitrogen and carbohydrate exhibited a decrease in response to both the auxins. 4-Cl-IAA, at a concentration of 10⁻⁸ M, generated the best response. Moreover, 4-Cl-IAA at other two concentrations (10⁻⁶ and 10⁻¹⁰ M) was much more active than any of the IAA concentration used.

2

Radioactive Mineralization in Pegmatites, of Dara-Um Swassi, Area North Eastern Desert, Egypt

88%

Shalaby M. , Osman A. , Ali M. , Ahamed F. , Ali B.

Bulletin of the Polish Academy of Sciences. Earth Sciences

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2002

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tom Vol. 50, nr 1

51-66

EN

The Dara-Um Swassi pluton is one of the well-exposed granitic batholiths in the North Desert. It is cut by pegmatites and dykes of different types running in harmony with the prevailing structural trends. The pegmatites are found as pockets and lenses especially in the peripheral zones and at different topographic levels. They usually have a NE-SW trend, which coincides with the main structural trend. The Dara-Um Swassi pegmatites are both, zoned and unzoned. An idealized zonal sequence from outer margin to the center is: (1) plagioclase, quartz, microcline-perthite with, or without muscovite and/or biotite (wall zone); (2) orthoclasc-perthite, quartz and muscovite (intermediate zone); (3) quartz of monophase type (core zone). In some zoned pegmatites, distinct dark alteration zones are found at contact between quartz core and intermediate zone in the radioactive cataclastic pegmatite. Unzoned pegmatites are of coarse-grained granitic composition. The two types of pegmatites contain fluorite, zircon, allanite, bastneasite and yttrian fluorite, while euxenite, curate, carnotite and thorianite minerals are only found in the zoned pegmatites. Whole rock chemical analyses of the host monzogranites and pegmatite wall zones provide strong evidence that pegmatites in a granitic system are attributed to magmatic differentiation of a volatile-enriched granitic magma of calc-alkaline composition. With respect to radioactivity, in the unzoned pegmatites average U content is 150 ppm; and average Th content is 99 ppm, the zoned pegmatites represent the most important radioactive sites. U and Th contents decrease from intermediate zones toward wall zones (av. = 143 ppm U, 105.5 ppm Th for intermediate zones, and 56.5 ppm U, 47 ppm Th for wall zones). The altered zones represent the most radioactive sites (av. = 233 ppm U, and 205 ppm Th); this is due to the alteration processes caused by late-stage hydrothermal solutions (haematitization, kaolinitization, chloritization and fluoritization).

3

Differential physiological and ultrastructural responses of cottonseeds under Pb toxicity

88%

Khan M. , Khan M. D. , Ali B. , Noor M. , Zhu S.-J.

Polish Journal of Environmental Studies

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2014

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tom 23

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nr 6

EN

Lead (Pb) is a toxic heavy metal that causes physiological and morphological changes in plants. Our current study was aimed at observing Pb-induced changes in seeds of two upland cotton varieties (TM-1 and Z- 747) that were exposed for 24 hours to various Pb concentrations (0, 50, 100, 300, and 500 μM). Seeds of TM-1 showed higher germination percentages, water uptake, and cell viability as compared to Z-747. Changes in nuclei shape, their partial disappearance, and increase in vacuole size were the initial signs of lead toxicity in Z-747, while TM-1 maintained its typical conformations. Cell wall thickening; increase in the number of mitochondria, protein, and lipid bodies; and vacuolation were more prominent in TM-1. In contrast, plasmolytic shrinkage and scattered cell organelles were the key characteristics of Z-747 at higher doses of Pb. Those observations demonstrated that seeds of TM-1 were more tolerant to Pb stress as compared to Z-747 and may be considered a preferred choice for culture on Pb-contaminated soils.

4

Priming-induced antioxidative responses in two wheat cultivars under saline stress

75%

Islam F. , Yasmeen T. , Ali S. , Ali B. , Faroog M. A. , Gill R. A.

Acta Physiologiae Plantarum

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2015

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tom 37

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nr 08

EN

Wheat, a glycophyte grown in tropical and subtropical regions, is frequently being subjected to soil salinity ultimately affecting the plant growth and yield. Focus of the present study was to evaluate the ameliorative efficiency of different seed priming methods including hydropriming and halopriming [KCl and CaCl2 (100 mM)] by observing change in the expression of antioxidant defense system and accumulation of phenolic as well as proline in the spring wheat Lu26s (salt tolerant) and Lasani-06 (salt sensitive), grown under salt stress of 100 mM NaCl. Results showed that salt stress provoked a marked decline in germination, growth and yield parameters as well as increased lipid peroxidation and hydrogen peroxide (H2O2) contents. However, higher accumulation of proline and low H2O2 contents were recorded in both cultivars under halopriming followed by hydropriming. Halopriming induced a significant increase in antioxidant enzyme activities (CAT, POD, APX) of salt-tolerant cultivar Lu26s, whereas such pattern of enhanced activities of antioxidant enzymes in cultivar Lasani-06 was also found but the content of these activities was less than control under saline regime. The cultivar Lu26s (salt tolerant) maintained lower Na+ and higher K+/Na+ ratio in leaves than salt-sensitive cultivar Lasani-06. Reason behind the loss of grain yield under salinity was found due to the reduction in the grain spike-1 in cultivar Lasani-06, while, in cultivar Lu26s, it was due to decrease in the size of grains. Enhanced germination, low proline and Na+ contents stimulated antioxidant activities as well as phenolic contents associated with improved salt tolerance in haloprimed plants. These results suggest that halopriming is an efficient approach for imparting tolerance in wheat against salinity stress.

5

Carbon Co-Deposition During Gas Reduction of Water-Atomized Fe-Cr-Mo Powder

75%

Ali B. , Kim T. S. , Choi S. H. , Seo S. J. , Maeng D. Y. , Lee C. G. , Park K. T.

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6

Effect of 28-homobrassinolide on the drought stress-induced changes in photosynthesis and antioxidant system of Brassica junca L.

75%

Fariduddin Q. , Khanam S. , Hasan S. A. , Ali B. , Hayat S. , Ahmad A.

Acta Physiologiae Plantarum

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2009

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tom 31

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nr 5

EN

To investigate the effect of exogenously applied 28-homobrassinolide (HBL) on drought-stressed plants, photosynthesis and antioxidant systems were examined in Indian mustard (Brassica juncea L.). Seedlings of Indian mustard were subjected to drought stress for 7 days at the 8–14 (DS1)/15–21 (DS2) days’ stage of growth and then returned to normal conditions of growth. These seedlings were sprayed with HBL (0.01 µM) at the 30-day stage and were sampled at 60 days to assess the changes in growth, photosynthesis and antioxidant enzymes. Plants exposed to stress at either of the stages of growth exhibited a significant decrease in growth and photosynthesis. The exposure of plants to stress at an earlier stage (DS1) was more inhibitory than that at a later stage (DS2). However, the follow-up treatment with HBL significantly improved the values of these parameters and also overcame the inhibitory effect of water stress. The activity of antioxidant enzymes [catalase (E.C. 1.11.1.6), peroxidase (E.C. 1.11.1.7) and superoxide dismutase (E.C. 1.15.1.1)] and proline content in leaves exhibited an increase in response to both the treatment factors, where their interaction had an additive effect. It was, therefore, concluded that the elevated antioxidant system, at least in part, was responsible for amelioration of the drought stress.

7

Carbon Co-Deposition During Gas Reduction of Water-Atomized Fe-Cr-Mo Powder

75%

Ali B. , Choi S. H. , Seo S. J. , Maeng D. Y. , Lee C. G. , Kim T. S. , Park K. T.

Archives of Metallurgy and Materials

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2017

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tom Vol. 62, iss. 2B

1119--1124

EN

The water atomization of iron powder with a composition of Fe-3Cr-0.5Mo (wt.%) at 1600°C and 150 bar creates an oxide layer, which in this study was reduced using a mixture of methane (CH4) and argon (Ar) gas. The lowest oxygen content was achieved with a 100 cc/min flow rate of CH4, but this also resulted in a co-deposition of carbon due to the cracking of CH4. This carbon can be used directly to create high-quality, sinter hardenable steel, thereby eliminating the need for an additional mixing step prior to sintering. An exponential relationship was found to exist between the CH4 gas flow rate and carbon content of the powder, meaning that its composition can be easily controlled to suit a variety of different applications.

8

The influence of new herbicide ZJ0273 on the total - and branched - chain amino acids in oilseed rape (Brassica napus L.) leaves as revealed by near-infrared spectroscopy

63%

Tian T. , Jin Z. , Ali B. , Guo X. , Liu F. , Zhang F. , Zhang W. , He Y. , Zhou W.

Acta Physiologiae Plantarum

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2014

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tom 36

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nr 08

EN

Propyl 4-(2-(4,6-dimethoxypyrimidin-2-yloxy) benzylamino)benzoate (ZJ0273) is a new herbicide which inhibits acetolactate synthase (ALS). The ZJ0273 is considered as safe for the environment and exhibits a satisfactory effect on weed control in the rapeseed field. ALS is the key enzyme of reactions in the biosynthesis of total amino acids (TAAs) especially branched-chain amino acids (BCAAs). This study reports the effect of ZJ0273 on BCAAs and TAAs in rapeseed leaves using near-infrared spectroscopy (NIRS) techniques. A decrease in TAAs and BCAAs contents was observed as the herbicide dosages were increased along with leaf senescence. The wavelengths 2,416 and 1,340 nm were selected to develop the NIRS model for detecting BCAAs and TAAs, and correlation coefficients of model’s prediction set were 0.9823, 0.9764, 0.9831, and 0.9968 for valine, isoleucine, leucine, and TAAs, respectively. The results indicated that 100 mg/L ZJ0273 was a safe dosage for oilseed rape as it did not show a significant effect on the contents of amino acids compared to other higher dosages (500 and 1,000 mg/L).

9

Cytotoxicity and antimicrobial activity of pivalic and benzoic acid complexed Cu and Mn complexes

63%

Ali B. , Tahir S. , Akhtar M. N. , Yameen M. , Ashraf R. , Hussain T. , Ghaffar A. , Abbas M. , Bokhari T. H. , Iqbal M.

Polish Journal of Environmental Studies

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2017

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tom 26

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nr 6

XX

The complexes of Cu and Mn metals with carboxylates (pivalic acid and benzoic acid) and imidazole were prepared and characterized. The synthesized complexes were screened for antimicrobial activity and cytotoxicity. The FTIR technique was used for characterization. The antibacterial assay revealed that the ligand and complexes are active against Escherichia coli, Staphylococcus aureus and Pasteurella multocida bacterial strains. The haemolytic assay revealed that [Cu(imi)(N₃)] and [MnIII(piv)(imi)(N₃)] were nontoxic, whereas [Cu(piv)(imi)] and [MnIII(Benz)(imi)(OCH₃)] showed moderate toxicity, and [Mn(Him)(N₃)₂] was highly toxic against human red blood cells (RBCs). Results revealed that Cu and Mn complexes with carboxylates (pivalic acid and benzoic acid) have antimicrobial activities. However, haemlytic assay revealed that the metal complex cytotoxicity was variable and biological activity evaluatuion of newly synthesized metals complexes is suggested for safe applications.

10

Fabrication of a Spherical Titanium Powder by Combined Combustion Synthesis and DC Plasma Treatment

63%

Choi S. H. , Ali B. , Hyun S. K. , Sim J. J. , Choi W. J. , Joo W. , Lim J. H. , Lee Y. J. , Kim T. S. , Park K. T.

Archives of Metallurgy and Materials

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2017

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tom Vol. 62, iss. 2B

1057--1062

EN

Combustion synthesis is capable of producing many types of refractory and ceramic materials, as well as metals, with a relatively lower cost and shorter time frame than other solid state synthetic techniques. TiO2 with Mg as reductant were dry mixed and hand compacted into a 60 mm diameter mold and then combusted under an Ar atmosphere. Depending on the reaction parameters (Mg concentration 2 ≤ α ≤ 4), the thermocouples registered temperatures between 1160°C and 1710°C . 3 mol of Mg gave the optimum results with combustion temperature (Tc) and combustion velocity (Uc) values of 1372°C and 0.26 cm/s respectively. Furthermore, this ratio also had the lowest oxygen concentration in this study (0.8 wt%). After combustion, DC plasma treatment was carried out to spheroidize the Ti powder for use in 3D printing. The characterization of the final product was performed using X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, and N/O analysis.

11

Performance of Time Hopping Impulse Radio in Ultrawideband Propagation Channels: Implications of UWB and Diversity Order Selection

63%

Khaqan A. , Gulfam S. M. , Riaz L. , Yasin A. , Ahmed A. , Jamil M. , Ali B. , Ali H. , Sharief H. , Riaz R. A.

Przegląd Elektrotechniczny

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2013

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tom R. 89, nr 7

69--73

EN

In this treatise, we quantify the effects of the UltraWideBand (UWB) on Time Hopping (TH) Impulse Radio (IR) operating in UWB propagation channels environment in terms of bandwidth utilization through diversity order selection. We select L strongest MultiPath Components (MPC) from Nr resolvable MPCs using Maximal Ratio Combining (MRC) in order to achieve maximum performance gain in single and full load scenarios. Three classical detectors have being used for analysis purposes named Correlation (Corr), Zero Forcing Detector (ZFD) and Minimum Mean Square Error (MMSE). Our results suggest that the diversity order L of 20 achieves maximum gain of 18dB and 12dB in single and full load Nu of 63 users scenarios, having spreading factor Ns of 63 over no diversity configuration. Hence, MPCs with delays greater than the TH chip time Tc are resolved by synchronization with the initial path of the received signal gives maximum performance gain.

PL

W artykule przedstawiono wyniki analizy dotyczącej działania techniki Time Hopping Impulse Radio, zastosowanej w komunikacji Ultra WideBand, pod kątem stopnia wykorzystania dostępnej przepustowości. W analizie zastosowano trzy typy detektorów: Corr, ZFD, MMSE. Wyniki badan wskazują, że gdy komponenty wielościeżkowe o opóźnieniach większych niż okres Time Hopping są synchronizowane z początkiem odbieranego sygnału, osiągana jest maksymalna efektywność działania.

12

Fabrication of a Spherical Titanium Powder by Combined Combustion Synthesis and DC Plasma Treatment

63%

Choi S. H. , Kim T. S. , Ali B. , Hyun S. K. , Sim J. J. , Choi W. J. , Joo W. , Lim J. H. , Lee Y. J. , Park K. T.

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13

Reaction Kinetics and Morphological Study of TiNb2O7 Synthesized by Solid-State Reaction

51%

Choi S. H. , Ali B. , Choi K. S. , Hyun S. K. , Sim J. J. , Choi W. J. , Joo W. , Lim J. H. , Lee T. H. , Kim T. S. , Park K. T.

Archives of Metallurgy and Materials

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2017

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tom Vol. 62, iss. 2B

1051--1056

EN

Although TiNb2O7 is regarded as a material with high application potential in lithium-ion batteries (LIBs) and solid-oxide fuel cells (SOFCs), it has been difficult to find suitable cost-effective conditions for synthesizing it on a commercial scale. In this study, TiNb2O7 compounds were synthesized by a solid state synthesis process. For stoichiometrically precise synthesis of the TiNb2O7 phase, the starting materials, TiO2 and Nb2O5 were taken in a 1:1 molar ratio. Activation energy and reaction kinetics of the system were investigated at various synthesis temperatures (800,1000,1200, and 1400°C) and for various holding durations (1,5,10, and 20 h). Furthermore, change in the product morphology and particle size distribution were also evaluated as a function of synthesis temperature and duration. Additionally, quantitative phase analysis was conducted using the Rietveld refinement method. It was found that increases in the synthesis temperature and holding time lead to increase in the mean particle size from 1 to 4.5 μm. The reaction rate constant for the synthesis reaction was also calculated.