Modal verbs are also called auxiliary verbs, helping verbs and modal auxiliaries. They are special auxiliary verbs that express the degree /of certainty of the action in the sentence, attitude or opinion of the writer concerning the action. These auxiliary verbs are can, could ,may, might, must, ought to, shall, should, will, would and had better. Modality is one of the most difficult aspects of learning English, because the form of modals does not follow the conventional rules of grammar, and there are so many meanings of modals that students often get confused about which modal to use. Also, many EFL learners face difficulty in choosing the proper modal verb that fit certain situations because each modal verb has many functions. The present study is conducted to investigate fourth-year-college students’ ability in signifying English modals appropriately and using them correctly. To fulfill the basic requirement of this study, the researchers organized a test, which consists of two questions; the first one is recognition, the second is production. The results show that the students have a real problem in recognizing and using modals.
The concept of -closedness, a kind of covering property for topological spaces, has already been studied with meticulous care from different angles and via different approaches. In this paper, we continue the said investigation in terms of a different concept viz. grills. The deliberations in the article include certain characterizations and a few necessary conditions for the -closedness of a space, the latter conditions are also shown to be equivalent to -closedness in a - almost regular space. All these and the associated discussions and results are done with grills as the prime supporting tool.
Background: Otitis media with effusion is characterized by accumulation of fluid in the middle ear in absence of acute inflammation and it is the most common cause of acquired hearing loss in children, and may negatively affect language development failure of medical treatment of middle ear effusion frequently require myringotomy and tympanostomy tube insertion.
Objectives: To determine tympanostomy tube complications of tube in children with chronic otitis media with effusion who were treated with Shah Grommet tube insertion.
Methods: The Medical records of 162 ears of 87 children (52 male and 35 female) were reviewed respectively, the patients ages wer
... Show MoreThe aim of the present research is to study the dissolution and transport process of
benzene as a light nonaqueous phase liquid (LNAPL) in saturated porous media.
Unidirectional flow at water velocities ranged from 0.90 to 3.60 cm/hr was adopted to study
this process in a three dimensional saturated sand tank (100 cm×40 cm×35 cm). This tank
represents a laboratory-scale aquifer. The aquifer was constructed by packing homogeneous
sand in the rectangular tank. The experimental results were used to characterize the
dissolution behavior of an entrapped nonaqueous phase benzene source in a three dimensional
aquifer model. The time invariant average mass transfer coefficient was determined at each
interstitial velocit
A niger, a fungus which doesn't have high ability to production lipid, this fungus has been select to investigate the non oleaginicity. In this search, there are explorations about: i) growth profile ii) enzymes profile iii) isoforms. Growth profile shows that this fungus doesn't have ability to accumulate lipid more than 6% while bio mass are around 10g/l in spite of the presence of glucose in the media till the end of cultivation time and excision of nitrogen within 24 hrs. In enzyme study, we investigate all lipogenic enzymes Malic enzyme (ME), Fatty acid synthase (FAS), ATP: Citrate lays (ACL), NAD+ isocitrate dehydrogenase (NAD+ICDH), Glucose-6-phosphate (G6PD), and 6-phosphogluconate dehydrogenase (6PGD), all these enzymes show, ac
... Show MoreAbstract Since unmethylated CpG motifs are more common in DNA from bacteria than vertebrates, and the unmethylated CpG motif has recently been reported to have stimulatory effects on lymphocytes, we speculated that bacterial DNA may induce inflammation in the urinary tract. To determine the role of bacterial DNA in lower UTI, we intraurethrally injected prokaryotic DNA (extracted from E. coli) in white mice and performed histopathological study for the kidneys and urinary bladders, 24 h after the exposure. The results showed infiltration of inflammatory cells, shrinkage of glomerulus and increase the capsular space, as well as edema formation in kidney tissues. Moreover, urinary bladder sections showed infiltration of inflammatory cells.
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Abstract
This study investigated the optimization of wear behavior of AISI 4340 steel based on the Taguchi method under various testing conditions. In this paper, a neural network and the Taguchi design method have been implemented for minimizing the wear rate in 4340 steel. A back-propagation neural network (BPNN) was developed to predict the wear rate. In the development of a predictive model, wear parameters like sliding speed, applying load and sliding distance were considered as the input model variables of the AISI 4340 steel. An analysis of variance (ANOVA) was used to determine the significant parameter affecting the wear rate. Finally, the Taguchi approach was applied to determine
... Show MoreThe aim of this research is to identify the availability of quality standards for the websites of the Palestinian TV channels and to provide an assessment of the quality standards used by the websites of TV Channels web sites in general and Palestinian TV channels in particular. Through the use of the method of media survey method descriptive methods, and the research has reached the difference in the application of quality standards for TV Channels sites in the web sites of Palestinian TV Channels, and the development of language of visual communication for the design of those sites in exchange for the lack of access to those sites of the technical possibilities that is Provided by the Internet.
The present paper describes and analyses three proposed cogeneration plants include back pressure steam-turbine system, gas turbine system, diesel-engine system, and the present Dura refinery plant. Selected actual operating data are employed for analysis. The same amount of electrical and thermal product outputs is considered for all systems to facilitate comparisons. The theoretical analysis was done according to 1st and 2nd law of thermodynamic. The results demonstrate that exergy analysis is a useful tool in performance analysis of cogeneration systems and permits meaningful comparisons of different cogeneration systems based on their merits, also the result showed that the back pressure steam-turbine is more efficient than other pro
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