The fate of the Wilson-Fisher fixed point in non-commutative \phi^4

In this article we study non-commutative vector sigma model with the most general \phi^4 interaction on Moyal-Weyl spaces. We compute the 2- and 4-point functions to all orders in the large N limit and then apply the approximate Wilson renormalization group recursion formula to study the renormalized coupling constants of the theory. The non-commutative Wilson-Fisher fixed point interpolates between the commutative Wilson-Fisher fixed point of the Ising universality class which is found to lie at zero value of the critical coupling constant a_* of the zero dimensional reduction of the theory, and a novel strongly interacting fixed point which lies at infinite value of a_* corresponding to maximal non-commutativity beyond which the two-sheeted structure of a_* as a function of the dilation parameter disappears.Comment: 19 pages, 7 figures, v2:one reference adde

The effects of different dietary vitamin C and iron levels on the growth, hematological and immunological parameters of rainbow trout Oncorhynchus mykiss fingerlings

A 60-days growth trial was conducted in a flow-through culture system to examine the effects of different dietary vitamin C and iron levels on the growth, hematological and immunological parameters of rainbow trout (Oncorhynchus mykiss) fingerlings (with average initial weight of 5.12 ± 0.02 g). Three levels of vitamin C (150, 200 and 250 mg kg^-1 diet) and iron (5, 7 and 9 mg kg^-1 diet) (as ferrous sulfate) and their combination were used to prepare diets used in nine experimental treatments with three replicates. The results revealed that the supplementation of basal diet with vitamin C and iron significantly affected the final body weight (FBW), total length (TL), feed conversion ratio (FCR) and specific growth rate (SGR). Among the haematological parameters haematocrit and mean corpuscular volume (MCV) were significantly influenced by vitamin C and iron. Results also showed that lysozyme and IgM concentrations significantly changed among dietary treatments. Based on the results of this study, it can be concluded that addition of vitamin C and iron to the basal diet of cultured rainbow trout will improve the growth rate and well-being of this fish

Developing high performance polymeric nano-composites for tribological applications

Polymers and their composites have been widely applied in different industrial sectors as alternatives to conventional metal-based materials, for the better performance of the system, increasing efficiency and cutting down operational costs. In those applications polymeric materials are sometime subjected to tribological loading conditions where external lubricants are not permissible and polymers’ self-lubricating ability is desirable in such tribo-contacts. In particular, high temperature is often the key factor determining the working conditions of polymers. Hence, high performance polymers (HPPs) have received increasing attention in last decades. In view of above-mentioned facts, the present research investigated the tribological performance of some important engineering polymers and their nanocomposites such as epoxy, PEEK, PPP and PBI. For example, nano-silica (SiO2), nano-rubber (CBTN) and titanium dioxide (TiO2) nano-particles have been incorporated in thermosetting epoxy resin and PEEK, respectively, to improve their tribological properties. To explore the effect of harsh environments during sliding wear, pin-on-disk tests of above-mentioned materials were carried out in dry, wet and elevated temperature regimes. Finally, attempts have been made to establish correlations between the basic mechanical properties of HPPs and their sliding wear behaviour. Various wear models to correlate the tribological aspects of HPPs and polymer nanocomposites with associated mechanical properties were examined along with experimental validation. In addition to that, underlying wear mechanisms were taken into account towards model developments. To develop a quantitative solution for wear prediction, the new computer techniques such as artificial neural network (ANN) may be helpful in the area. Accordingly, the ANN was employed to find the general wear trend of materials

Remote Sensing as a Precision Farming Tool in the Nile Valley, Egypt

Detecting stress in plants resulting from different stressors including nitrogen deficiency, salinity, moisture, contamination and diseases, is crucial in crop production. In the Nile Valley, crop production is hindered perhaps more fundamentally by issues of water supply and salinity. Predicting stress in crops by conventional methods is tedious, laborious and costly and is perhaps unreliable in providing a spatial context of stress patterns. Accurate and quick monitoring techniques for crop status to detect stress in crops at early growth stages are needed to maximize crop productivity. In this context, remotely sensed data may provide a useful tool in precision farming. This research aims to evaluate the role of in situ hyperspectral and high spatial resolution satellite remote sensing data to detect stress in wheat and maize crops and assess whether moisture induced stress can be distinguished from salinity induced stress spectrally. A series of five greenhouse based experiments on wheat and maize were undertaken subjecting both crops to a range of salinity and moisture stress levels. Spectroradiometry measurements were collected at different growth stages of each crop to assess the relationship between crop biophysical and biochemical properties and reflectance measurements from plant canopies. Additionally, high spatial resolution satellite images including two QuickBird, one ASTER and two SPOT HRV were acquired in south-west Alexandria, Egypt to assess the potential of high spectral and spatial resolution satellite imagery to detect stress in wheat and maize at local and regional scales. Two field work visits were conducted in Egypt to collect ground reference data and coupled with Hyperion imagery acquisition, during winter and summer seasons of 2007 in March (8-30: wheat) and July (12-17: maize). Despite efforts, Hyperion imagery was not acquired due to factors out with the control of this research. Strong significant correlations between crop properties and different vegetation indices derived from both ground based and satellite platforms were observed. RDVI showed a sensitive index to different wheat properties (r > 0.90 with different biophysical properties). In maize, GNDVIbr and Cgreen had strong significant correlations with maize biophysical properties (r > 0.80). PCA showed the possibility to distinguish between moisture and salinity induced stress at the grain filling stages. The results further showed that a combined approach of high (2-5 m) and moderate (15-20) spatial resolution satellite imagery can provide a better mechanistic interpretation of the distribution and sources of stress, despite the typical small size of fields (20-50 m scale). QuickBird imagery successfully detects stress within field and local scales, whereas SPOT HRV imagery is useful in detecting stress at a regional scale, and therefore, can be a robust tool in identifying issues of crop management at a regional scale. Due to the limited spectral capabilities of high spatial resolution images, distinguishing different sources of stress is not directly possible, and therefore, hyperspectral satellite imagery (e.g. Hyperion or HyspIRI) is required to distinguish between moisture and salinity induced stress. It is evident from the results that remotely sensed data acquired by both in situ hyperspectral and high spatial resolution satellite remote sensing can be used as a useful tool in precision farming in the Nile Valley, Egypt. A combined approach of using reliable high spatial and spectral satellite remote sensing data could provide better insight about stress at local and regional scales. Using this technique as a precision farming and management tool will lead to improved crop productivity by limiting stress and consequently provide a valuable tool in combating issues of food supply at a time of rapid population growth

Measurement of some Air Pollutantsin Printing Units and Copy Centers Within Baghdad City

إن انبعاث المواد الدقائقية من الأوراق المتناهية الصغر فضلا عن الأحبار والمذيبات العضوية خلال عملية تشغيل ماكينات الطباعة والاستنساخ تشكل خطرا على صحة الإنسان بالأخص بعد التعرض طويل الأمد في بيئات العمل المغلقة . أجريت الدراسة الحالية في بعض دور الطباعة ومراكز الاستنساخ في مدينة بغداد خلال شهري شباط ونيسان، وأثبتت الدراسة حدوث مشكلة تلوث الهواء فيما يتعلق بمحتويات الرصاص والزنك في جميع مواقع الدراسة .تم تحديد تركيز الرصاص والزنك والنحاس من خلال جمع العينات بوساطة جهاز جمع عينات الهواء وبعدها تم ترشيح العينات وهضمها وتحديد نسبة العناصر الثقيلة بوساطة جهاز المطياف الذري اللهبي، أما المواد الدقائقية تم قياسها بوساطة جهاز قياس الدقائق العالقة في الهواء ، واستعمل جهاز قياس الغازات الملوثة للهواء لقياس غاز ثنائي أكسيد لنتروجين وثنائي أكسيد الكبريت وأول أكسيد الكربون والمركبات العضوية المتطايرة . سجل أعلى تركيز للرصاص والزنك في هواء المطابع (2.75 مايكرو غرام/م3 ) و (51.95 مايكرو غرام /م3) على التوالي . بالمقابل سجل أعلى قيمة معنوية نحاس في  هواء مكاتب الاستنساخ (0.65 مايكرو غرام /م3) مقارنة بدور الطباعة . سجل أعلى تركيز للمواد الدقائقية الناعمة (PM2.5) التي يكون قطرها أقل من 2.5 مايكرو متر(44.50 مايكرو غرام /م3) في دور الطباعة يليها أعلى تركيز للمواد الدقائقية الخشنة المستنشقة(PM10)  التي يتراوح قطرها بين 2.5 الى 10 مايكرو متر والدقائق الكلية العالقة (477.66 و667.00 مايكرو غرام /م3) في دور الطباعة على التوالي . أظهرت النتائج أعلى تركيز لغاز أول أكسيد الكربون CO (6.13 جزء في المليون) والمركبات العضوية المتطايرة ((VOCs (21.88 جزء في المليون) في دور الطباعة بينما سجل أعلى تركيز لغاز ثنائي أكسيد النتروجين(NO2)  (1.44 جزء في المليون) في مراكز الاستنساخ . تجاوزت تركيز الرصاص والزنك والنحاس والمواد الدقائقية PM2.5و PM1والدقائق الكلية العالقة المستويات المسموح بها في جميع مواقع الدراسة على عكس مستويات أول أكسيد الكربون وثنائي أكسيد النتروجين وثنائي أكسيد الكبريت والمركبات العضوية المتطايرة التي كانت ضمن محددات جودة الهواء المسموح بها .Emissions of particulate matter from nanopapers as well as inks and organic solvents during the printing operationand copying machines constitute a threat to human health, especially with long time exposure in closed working environments. The present study was conducted in some printing houses and copying centers of Baghdad city during February and April  .The studyproved the occurrence of an air pollution problem concerning lead and zinc contents in all the study sites. The levels of Pb, Zn and Cu were collected by low volume sampler from the air of the study sites then filter papers digested and determined the heavy metals by flame atomic spectrophotometer. Particulate matter was measured by Aerocet, Microtector  meter device was used to measure nitrogen dioxide, sulphur dioxide, carbon monoxide and volatile organic compounds . The highest concentrations of lead and zinc were recorded in the printing houses air (2.75μg/m3) and (51.95μg/m3) respectively. In contrast,copper concentration in the copying offices air recorded a significantly higher value (0.65μg/m3) (P>0.05) as compared to that in printing houses. Fine particulate matter(PM2.5)(particles diameter < 2.5 μm) hasrecorded the highest concentration (44.50μg/m3) in printing houses, followed by the highest concentrations of inhalable coarse particulate matter (PM10)  (particles with diameter  of 2.5 to 10 μm)  and total suspended particulates (TSP)(the total of solid particles) (477.66 and 667.00μg/m3) respectively in printing houses. The results obviously showed the highest concentrations of carbon monoxide (CO) (6.13 ppm) and volatile organic compounds (VOCs) (21.88 ppm) in  printing houses, while nitrogen dioxide (NO2) recorded its highest concentration (1.44 ppm) in copy centers. Lead, zinc, copper, PM2.5, PM10 and TSP concentrations exceeded the permissble levels in all study sites converselywith the levels of carbon monoxide , nitrogen dioxide, sulphur dioxide(SO2) and volatile organic compounds that were within permissible air quality standards

Dynamic Soil Pressures on Vertical Walls

A summary is presented of recently contributed simple approximate solutions for the dynamic pressures and the associated forces induced by ground shaking on rigid vertical walls. The walls are presumed to be either straight or circular in plan and to retain a uniform viscoelastic soil stratum of constant thickness and infinite extent in the horizontal direction. Both the walls and the stratum are considered to be supported on a non-deformable base undergoing a space-invariant, uniform horizontal motion. The effects of both harmonic and earthquake-induced excitations are examined, and comprehensive numerical data ate presented which elucidate the underlying response mechanisms and the effects and relative importance of the various parameters involved. A brief review is then included of available simple, approximate schemes for modeling the systems examined. Finally, the sources and magnitudes of the errors that may result from the use of these models are identified, and modifications are proposed with which the responses of the systems may be defined correctly. In the proposed modifications, the soil stratum is modeled by a series of elastically supported semi-infinite layers with distributed mass. The concepts involved are introduced for the straight wall and are then applied to the embedded cylindrical system

The Application of Water Jets in Coal Mining

Water is one of the natural erosion agents which through time has changed the face of the earth. Application of this principle to remove earth and rock by man is a long established technique. This paper briefly describes the changes in technology which have brought the application of water jets from the slow erosion of soil to the point where in Canada some 3,400 tons per shift are currently mined in a coal mine using high pressure water jet technology. The use of water jets has shown sufficient promise that there are several research programs currently being funded by the U.S. Bureau of Mines and other Federal agencies in the field of excavation technology. Three current areas of water jet mining are described. The first is the use of water at 10,000 psi as a modification of the cutting head of a longwall mining machine. The work which is being carried out at the University of Missouri is briefly described with the rationale for the jet parameters chosen for the experimentation. The second method of mining is a project currently under way in Canada where in a seam 50 ft thick and dipping at an angle of some 40 degrees, a low pressure, high volume flow rate up to 1,500 gallons per minute water jet system produced up to 3,400 tons per manshift. The third method of mining is an experimental program being carried out by Flow Research, Inc. in Washington state. With this method coal is mined from underground seams to boreholes driven from the surface, coal being reamed to the borehole by high pressure water jets and crushed in the bottom of the borehole prior to being pumped out of the borehole for external usage. This method does not, therefore, require access to the underground

Simulation of soot formation using particle dynamics with one dimensional nucleation mode

Journal ArticleTwo soot formation models using particle dynamics with one-dimensional nucleation mode directly coupled with gas phase chemistry are tested on three ethylene and three methane laminar premixed flames. These models demonstrate strength in the prediction of concentration profiles of major combustion products and critical intermediates, and the characteristics of soot particles. These models extend the practicability of simulation beyond the prediction of soot volume fraction and estimate the mean particle diameter quite well especially for methane flames. In particular, our second model expands the range of fuels that can be simulated, and also correctly predicts the effects of C/O ratio on the soot formation process. The strength and weakness of these models are investigated and new features are identified for the development of next generation of soot models