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Effects of Zero Tillage and Residue Retention on Soil Quality in the Mediterranean Region of Northern Syria

Open Journal of Soil Science 2014年第3期4卷 109-125页

作者： Rolf Sommer Colin Piggin David Feindel Muhammad Ansar Lona van Delden Kayoko Shimonaka Jihad Abdalla Osama Douba George Estefan Atef Haddad Rousheen Haj-Abdo Ali Hajdibo Pierre Hayek yaseen khalil Ahmed Khoder John Ryan International Center for Agricultural Research in the Dry Areas (ICARDA) Aleppo Syria nternational Center for Agricultural Research in the Dry Areas (ICARDA) Aleppo Syria nternational Center for Tropical Agriculture CIAT Nairobi Kenya

Zero-tillage (ZT) and crop residue retention on the soil surface—two components of Conservation Agriculture (CA)—have been identified as promising management practices for sustainable agri- cultural intensification for some time. However, CA technology uptake by farmers in the dry areas of West Asia and North Africa (WANA) has yet to happen large-scale, even though the positive im- pact on yield has been demonstrated repeatedly. To explain the observed consistent increases in crop yield under ZT, a range of soil quality indicators were regularly monitored during 2008 to 2012 in the long-term ZT/CA trials at the headquarters of the International Center for Agricultural Research in the Dry Areas (ICARDA) in northern Syria. Results showed that CA had a positive im- pact on soil fertility. This was measurable by higher soil organic matter (SOM) and microbial bio- mass contents, increased levels of extractable phosphate, sometimes (but not always) higher amounts of larger water-stable soil aggregates, increased soil infiltration capacity and soil water retention. The buildup of SOM and associated carbon (C) sequestration was in the range of 0.29 Mg C/ha/yr, i.e. rather modest. High amounts of surface residues delayed the desiccation of the topsoil during the fallow period, but could not diminish the overall longer-term drying of the topsoil. The observed positive changes in soil quality were little, but nevertheless, in combination with the economic savings that ZT offers, this type of agricultural intensification provides an attractive op- tion for farmers in WANA, from the standpoints of economy and ecological efficiency.

关键词： Conservation Agriculture Soil Fertility Indicators Soil Water Evaporation Water Infiltration Water Stable Aggregates Soil Carbon Sequestration

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Synthesis of Yb<sup>3+</sup>Doped TiO<sub>2</sub>Nano Particles Powder as IR Filter via Sol-Gel

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Advances in Materials Physics and Chemistry 2013年第4期3卷 214-216页

作者： Mohammed A. Hamza Asmaa Sh. khalil Hanna M. yaseen College of Science for Woman Baghdad University Baghdad Iraq College of Science Baghdad University Baghdad Iraq

Ytterbium doped TiO2 nano-particles were prepared via Sol-Gel Technique under varying conditions to investigate the effects of Ytterbium ion doping on the Titania optical properties in MID IR range. X-ray diffraction analyses show that prepared Yb3+ doped TiO2 samples have polycrystalline structure in Anatas phase. FTIR spectrums for pure and doped samples after annealing process show a single transmission peak at wave number around 1145 cm-1. Transmission rate of this peak depends on Yb3+ concentrations and its value rises from 1.82% (for pure TiO2) to 58.1% (for doped with 1.13 wt% Yb3+). Slightly peak shift occurs at a lower doping rate with no further response to higher concentration rate. FTIR spectra gives a good indication in direction of preparation of optical band-pass filter at a wavelength around 8.733 μm (~1145 cm-1).

关键词： Sol-Gel Nano Technology TiO2 MID IR Optical Filter

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Diagnostic value of dobutamine stress Doppler tissue imaging in diabetic patients with suspected coronary artery disease

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World Journal of Cardiovascular Diseases 2011年第1期1卷 1-12页

作者： Mohamed Fahmy Elnoamany Hala Mahfouz Badran Tarek Salah khalil Abdalla Mostafa Kamal Amany Ragab Serag Rehab Ebraheem yaseen 不详

Background: Coronary artery disease (CAD) is often silent in diabetic patients, and it is typically in ad-vanced stages of development by the time it manifests. Various forms of stress testing have been investigated to detect obstructive CAD in diabetes mellitus. Ob-jectives: To assess the diagnostic value of dobutamine stress pulsed-wave Doppler tissue imaging (DTI) compared with standard wall motion analysis in de-tection of myocardial ischemia in diabetic patients with suspected CAD. Methods: The study comprised 46 diabetic patients with suspected CAD underwent dobutamine stress echocardiography (DSE) with DTI within 4 weeks before coronary angiography(CA). Dobutamine infusion started at 5 μ/kg/min and in-creased up to 40 μ/kg/min with additional atropine during submaximal heart rate responses. In addition to wall-motion score index (WMSI) analysis, pulsed- wave DTI examination of basal and mid segments of posteroseptal, lateral, anterior, inferior and antero- septal walls was performed. Myocardial velocities were measured at rest in the apical 4, 3 and 2-cham- ber views. The measurements were repeated at low dose (10 - 15 μ/kg/min) and at peak stress (40 μ/kg/min). DTI measurements included peak systolic velocity (S), peak early diastolic velocity (E) and peak late diastolic velocity (A) and the results were com-pared to WMSI analysis. Patients were classified into two groups according to CA results;group (I) di-abetics with positive CA (n = 27) and group (II) di-abetics with negative CA (n = 19). Results: There was no significant difference between the two groups in duration of diabetes, global WMSI at rest or the ? changes (stress-rest/rest) of WMSI (P > 0.05). Global S and global E were significantly lower in group I compared to group II at peak stress (11.3 ± 3.7 cm/sec vs. 14.5 ± 2.2 cm/sec, p < 0.01) and (11.3 ± 1.6 cm/sec vs. 13.1 ± 2.1 cm/sec, p < 0.01) respectively. The cutoff points for global S and global E to detect obstructive CAD in diabetics were

关键词： Doppler Tissue Imaging Dobutamine Stress Diabetes Mellitus

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