277 research outputs found

    Critical analysis of portable web-tension measuring equipment

    Get PDF
    For satisfactory production or conversion of continuous material in web form it is generally important to control the tension in the web. The material may be plastics, paper or metal strip; conversion processes include web-fed printing or packaging machines and strip rolling mills. As speeds of production increase it is more likely that relatively high frequency tension perturbations may occur due to interaction between material properties and machine performance characteristics. This could result in frequent breakage of the web or unsatisfactory quality of the product. It is therefore of paramount importance to be able to measure and control tension variations accurately and with an adequate speed of response. The objectives of this investigation are to determine, by direct experiment and analytically, the limitations in static accuracy and dynamic performance of equipment for measurement of web tension. [Continues.

    Vibration Control in MEMS Resonator Using Positive Position Feedback (PPF) Controller

    Get PDF
    In this paper, the vibration of a micro-electromechanical resonator with positive position feedback controller is studied. The analytical results are obtained to the first order approximation by using the multiple scale perturbation technique. The stability of the steady-state solution is presented and studied applying frequency response equations near the simultaneous primary and internal resonance cases. The effects of the controller and some system parameters on the vibrating system are studied numerically. The main result of this paper indicates that it is possible to reduce the vibration for the resonator system

    IMPACTS OF CYANOBACTERIA AND BRADYRHIZOBIUM INOCULATION ON LUPINE PLANTS UNDER DIFFERENT NITROGEN RATES IN SANDY SOIL

    Get PDF
    A field experiment was conducted in sandy soil at Ismailia Agricultural Research Station, (Ismailia Governorate, Egypt, in two successive winter seasons of 2015/2016 and 2016/2017. The experiment aimed to study the response of lupine plants (Lupinus albus L.) variety Giza 2 to cyanobacteria applied with different methods under different nitrogen fertilizer rates and inoculated with rhizobia. Results revealed that application of cyanobacteria generally increased the mean values of nodules number, dry weight of nodules and shoot dry weight of lupine plants, nitrogen uptake, biological activity of the soil rhizosphere lupine plants, yield, yield components and seed protein content as compared to those recorded by the control treatment without cyanobacteria. Increasing nitrogen rates decreased the mean values of both nodules number and dry weight of nodules. On the contrary, increasing nitrogen rate up to 100% of the recommended one increased all the other tested parameters. The highest values of these parameters were recorded when cyanobacteria were applied as dry + soaking combined with 75 % N rate expect for those of number and nodules the dry weight of nodules that gave their highest values when the lupine plants received the treatment of dry + soaking combined with 50 % N rate. In conclusion, the use of cyanobacteria along with rhizobia as renewable nitrogen source for lupine production can save 25% N from that required for lupine

    EVALUATION OF GROUNDWATER QUALITY OF SIWA OASIS

    Get PDF
    In discussing the water quality evaluation for use in different purposes, the author will briefly examine some of the major important water quality standards. These standards serve as a basis for appraisal of the results of chemical water analysis in terms of suitability of the water for various intended uses. According to total dissolved salts (TDS),  major  ions as cations ( Ca2+, Mg2+, Na+, K+), anions (CO₃2â», HCO₃â»Â  ,SOâ‚„2â», Clâ»), with some heavy metals such as Al3+, B3+ , Cd2+, Co2+, Cr3+, Cu2+, Fe3+, Mn2+,  Mo2+, Ni2+,  Pb2+, Sr2+, V2+   and Zn2+  The results  indicate  that  the samples of Nubian sandstone aquifer is suitable for drinking of human and livestock , suitable for laundry purposes and for irrigation. While the samples of Fractured dolomite limestone aquifer are unsuitable for drinking and irrigation.Â

    The Relationship of Sperm Motility Pattern and Its Ability to Agglutinate with Vaginal Sperm Selection, Uptake in Sperm Storage Tubules and Competitiveness

    Get PDF
    To ensure survival, some unique features can be distinguished in birds that help them maintain reproduction. These features include the ability to store sperm for long periods within the utero-vaginal junction, a high sperm concentration per ejaculate, and polyspermy fertilization. Sperm face many challenges prior to fertilization. After copulation, most ejaculated sperm exit the female reproductive tract, and less than 1% continue in an attempt to achieve fertilization. In addition, egg size is substantially larger than sperm size because of the presence of the egg yolk. This results in a large number of sperm penetrating the egg away from the oocyte. These challenges have triggered evolutionary changes to maintain the existence of many species, such as the enormous relative size of the testis, which produces billions of sperm each day, and the ability to store viable sperm for long periods in the oviduct to ensure asynchronous fertilization. This chapter discusses several contemporary and sometimes controversial points regarding sperm behavior and their storage in the oviduct

    Partial dietary fish meal replacement with cotton seed meal and supplementation with exogenous protease alters growth, feed performance, hematological indices and associated gene expression markers (GH, IGF-I) for Nile tilapia, Oreochromis niloticus

    Get PDF
    A 12-week feeding trial was conducted to evaluate the effect of different ratios of fish meal (FM): cotton seed meal (CSM) without or with inclusion of exogenous protease in diets on growth performance, hematology, digestibility and selected gene expression markers (GH and I (IGF-I) of juvenile Nile tilapia. The experimental diets were categorized into three groups; the first group CSM1 which contained fish meal protein: cotton seed meal protein (FM: CSM = 2:1), the second group CSM2 which contained FM: CSM = 1:1 and the third one CSM3 contained FM: CSM = 1:2 on protein content based. All groups were supplemented with exogenous protease at 0 and 2500 U kg−1 diet, respectively. All diets were fed to fish (initial body weight 11.62 ± 0.03 g fish−1) in triplicate aquaria twice daily. The higher weight gain (WG), protein efficiency ratio (PER) and best feed conversion ratio (FCR) were recorded by fish fed CSM1 and CSM2 and supplemented with 2500 U protease/kg diet. The highest apparent digestibility coefficient of crude protein, crude lipid and digestible energy, and apparent availability coefficient of essential amino acids were obtained by fish receiving CSM1 and CSM2 supplemented with protease (2500 U protease kg−1 diet). The highest mean values of Hb, Htc and RBCs were recorded in fish fed CSM1 and CSM2 supplemented with protease enzyme (2500 U protease kg−1 diet). Serum of alanine and aspartate aminotransferase activities were improved due to dietary protease (2500 U protease kg−1 diet) supplementation, also, fish received the diets supplemented with protease 2500 U kg−1 diet generally had higher total protein, albumin, calcium and phosphorus than those fed diets without supplement. The highest growth hormone (GH) gene expression in brain and liver of tilapia were obtained in the group fed CSM3 and un-supplemented with protease enzyme followed by CSM2 (un-supplemented). On the other hand, tilapia fed CSM1 and CSM2 supplemented with protease enzyme showed the highest values of gene expression of insulin like growth factor I (IGF-I) in brain and liver of tilapia compared to other groups. Results above showed that supplementation of protease can improve growth, nutrient assimilation, and hematology and alter gene expression of GH and IGF-I of Nile tilapia

    Functional modelling of a novel mutation in BBS5.

    Get PDF
    BACKGROUND: Bardet-Biedl syndrome (BBS) is an autosomal recessive ciliopathy disorder with 18 known causative genes (BBS1-18). The primary clinical features are renal abnormalities, rod-cone dystrophy, post-axial polydactyly, learning difficulties, obesity and male hypogonadism. RESULTS: We describe the clinical phenotype in three Saudi siblings in whom we have identified a novel mutation in exon 12 of BBS5 (c.966dupT; p.Ala323CysfsX57). This single nucleotide duplication creates a frame shift results in a predicted elongated peptide. Translation blocking Morpholino oligonucleotides were used to create zebrafish bbs5 morphants. Morphants displayed retinal layering defects, abnormal cardiac looping and dilated, cystic pronephric ducts with reduced cilia expression. Morphants also displayed significantly reduced dextran clearance via the pronephros compared to wildtype embryos, suggesting reduced renal function in morphants. The eye, kidney and heart defects reported in morphant zebrafish resemble the human phenotype of BBS5 mutations. The pathogenicity of the novel BBS5 mutation was determined. Mutant mRNA was unable to rescue pleiotropic phenotypes of bbs5 morphant zebrafish and in cell culture we demonstrate a mislocalisation of mutant BBS5 protein which fails to localise discretely with the basal body. CONCLUSIONS: We conclude that this novel BBS5 mutation has a deleterious function that accounts for the multisystem ciliopathy phenotype seen in affected human patients

    The sample of choice for detecting Middle East respiratory syndrome coronavirus in asymptomatic dromedary camels using real-time reverse-transcription polymerase chain reaction

    Get PDF
    The newly identified Middle East respiratory syndrome coronavirus (MERS-CoV), which causes severe respiratory disease, particularly in people with comorbidities, requires further investigation. Studies in Qatar and elsewhere have provided evidence that dromedary camels are a reservoir for the virus, but the exact modes of transmission of MERS-CoV to humans remain unclear. In February 2014, an assessment was made of the suitability and sensitivity of different types of sample for the detection of MERS-CoV by real-time reverse-transcription polymerase chain reaction (RT-PCR) for three gene targets: UpE (upstream of the E gene), the N (nucleocapsid) gene and open reading frame (ORF) 1a. Fifty-three animals presented for slaughter were sampled. A high percentage of the sampled camels (79% [95% confidence interval 66.9-91.5%, standard error 0.0625]; 42 out of 53) were shown to be shedding MERS-CoV at the time of slaughter, yet all the animals were apparently healthy. Among the virus-positive animals, nasal swabs were most often positive (97.6%). Oral swabs were the second most frequently positive (35.7%), followed by rectal swabs (28.5%). In addition, the highest viral load, expressed as a cycle threshold (Ct) value of 11.27, was obtained from a nasal swab. These findings lead to the conclusion that nasal swabs are the candidate sample of choice for detecting MERS-CoV using RT-PCR technology in apparently healthy camels
    corecore