The study of biopolymers and their derivative materials had received a considerable degree of attention from researchers in the preparation of novel material. Biopolymers and their derivatives have a wide range of applications as a result of their bio-compatibility, bio-degradability and non-toxicity. In this paper, chitosan reacted with different aldehydes(2,4 –dichloro- benzaldehyde or 2-methyl benzaldehyde), different ketones (4-bromoacetophenone or 3-aminoacetophenone) to produce chitosan schiff base (1-4) . Chitosan schiff base (1-4) reacted with glutaric acid or adipic acid in acidic media in distilled water according to the steps of Fischer and Speier to produce compounds (5-12) respectively. Grafted chitosan (5-12) blended with synthetic polymer PVA to produce compounds (13-20), then these polymers were blended with nano Ag by using a hotplate stirrer for 60 min to produce nanocomposites. The synthesized polymers were identified via spectral analysis techniques, including FTIR , 1H-NMR and scanning electron microscope (SEM). Finally, studied anti-bacterial activities of some of the prepared polymers.
In This paper, CuO thin films having different thickness (250, 300 , 350 and 400) nm were deposited on glass substrates by thermal vacuum evaporator. The thermal oxidation of this evaporated film was done in heated glass at temperature (300 in air at one hour. The study of X-ray diffraction investigated all the exhibit polycrystalline nature with monoclinic crystal structure include uniformly grains. Thin film’s internal structure topographical and optical properties. Furthermore, the crystallization directions of CuO (35.54 , 38.70 ) can be clearly observed through an X-ray diffraction analysis XRD, Atomic Force Microscope AFM (topographic image) showed that the surface Characteristics , thin films crystals grew with increases in either
... Show MoreBackground: With the increasing demands for adult orthodontics, a growing need arises to bond attachments to porcelain surfaces. Optimal adhesion to porcelain surface should allow orthodontic treatment without bond failure but not jeopardize porcelain integrity after debonding.The present study was carried out to compare the shear bond strength of metal bracket bonded to porcelain surface prepared by two mechanical treatments and by using different etching systems (Hydrofluoric acid 9% and acidulated phosphate fluoride 1.23%). Materials and Methods: The samples were comprised of 60 models (28mm *15mm*28mm) of metal fused to porcelain (feldspathic porcelain). They were divided as the following: group I (control): the porcelain surface left u
... Show MoreThe study aims to determine the organizational monitoring mechanism in target organization as well as knowing the suffocation of work. The study depends on a questionnaire as a tool of collecting data on distributed random sample involved (45) person from different levels in manufacturing isphelt Dohuk. The study depends on some hypothesis, the most significant one is that there is not impact of organizational monitoring of suffocation especially on the target organization.
This search seeks to know the trends of academics in the field of Press and audio, video and read press about paper press compared with continued development and widespread deployment of web journalism. This research belongs to descriptive studies which depends on sample survey approach adopted by five-meter design measuring trends. It contains 28 items having applied honesty and reliability transaction and the scale form is distributed to the sample studied of about 110 professors and then the researcher collects them and then applying the appropriate statistical program to get the results. This search seeks to know the trends of academics in the field of Press and audio, video and read press about paper press compared with continu
... Show Moreكان لسياسات االحتالل دور بارز في فشل مشروع إعادة بناء الدولة في افغانستان، وفي الوقت نفسه تتحمل دول االحتالل المسؤ و لية الكاملة عن بعض هذه ً كبي ارً السياسات مثل عدم التخطيط الجيد لمرحلة االحتالل وإعادة بناء الدول ة، ثم إن جزءا من فشل هذه السياسات يرجع الى البيئتين المحلية واإلقليمية ، كذلك كان للخبرة السياسية والدستورية وللواقع االجتماعي الثقافي األفغاني تأثيرهما المهم في قدرة المجتمع األفغاني ً على قبول
... Show MoreThe main purpose of the present research is to identify emotional intelligence for college students and its relation to gender (male-female) , and to identify shyness for college students and its relation to gender(male-female)and to identify the relationship between emotional intelligence and shyness. The sample of the present research consisted of (200) college students , (100)male students and (100)female students randomly selected. scale for measuring emotional intelligence as prepared consists of (46) items according to Golmans theory distributed into five subscales and these are : (self-awareness , emotion management, motivation, sympathy and social skills) and Alobaidi shyness scale is used to assess shyness and it consist
... Show MoreThe words in the Holy Qur’an are distinguished by the
accuracy of expression, their elegance, the lightness of their
performance, the harmony of their timbre, as well as the ease of
their pronunciation. We find the coarse words in which the
movement of sounds and the hesitation of the soul are mixed, as
it was distinguished by the abundance of its words indicating the
same meaning without a phenomenon that the reader or the
listener notices
El español es una lengua hablada por una ingente comunidad que abarca varios cientos de millones de personas. Son muchas las palabras con distintos significados que se escriben de similar manera. Hablamos, por ejemplo, de dos de ellas: el adjetivo solo y el adverbio sólo.
En este trabajo se plantea un estudio del adverbio sólo, palabra invariable cuya función consiste en (complementar la significación del verbo) y solo es un adjetivo (califica a un sustantivo).¿Cómo diferenciarlas para evitar errores ortográficos? Así, en estos casos (solo/ sólo), la distinción la da la tilde en la primera vocal. Ésta es la
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