تعد التجارب المختبرية من أهم الوسائل التي تمكن من فهم خصائص المواد الكيميائية وسلوكها، كما إنها الوسيلة الوحيدة لتحضير المركبات الكيميائية المختلفة. وقد أدى تطور التكنولوجيا في الوقت الحاضر إلى إستخدام أدوات وأجهزة قياس في المختبر مكنت من زيادة دقة نتائج التجارب وسرعة الحصول عليها. أن تفعيل المختبر وإجراء الأنشطة العملية يمكن أن تحقق عدة أمور منها : 1- تُنمي في الطالب مهارات التفكير العلمي ( الملاحظة ، وتحديد المشكلة، وفرض الفروض، وإختبار الفروض، وإختيار الفرض الصحيح ، الإستنتاج والتعميم ) 2- تنمية القدرة على حل المشكلات والتفكير الإبداعي . 3- تمكن الطالب من تكوين المفاهيم بدلاً من المعرفة المجردة . 4- تساعد الطالب على تكوين الميول والإتجاهات العلمية ونوع الإختصاص في المستقبل . 5- تساعد على ترسيخ المعلومة وبقاء أثر التعلم فترة أطول . 6- تكسب الطالب طرق التعامل مع الأدوات المختبرية والمواد الكيميائية والتعرف على مخاطرها عن قرب وفهم قوانين وقواعد السلامة في المختبر وتطبيقها والمحافظة على سيرالعمل والآلات والأجهزة الموجودة في المختبر. 7- بث روح التعاون بين الطلاب بين المجاميع المختبرية . ويغطي هذا الكتاب مما يحويه من المعلومات الضرورية الوافية لمساقين في الكيمياء اللاعضوية وخاصة في التعرف على الجدول الدوري للعناصر وكل مايحتاجه الطالب في الالمام بالمعلومات التي تفيده من خلال التعرف على المختبرات العملية والتي تخص المرحلة الثانية . ويتميز هذا الكتاب بشموله بالتجارب العملية لثلاثين تجربة والتي تخص حول مركبات عناصر في الجدول الدوري. ويعتبر هذا الكتاب كمدخل في توضيح العلاقة بين المنهج النظري والمنهج العملي بشكل مترابط المفاهيم من خلال تعرف الطالب على التجارب العملية لما لها من مجالات تطبيقية في بيئته. وإشتمل الكتاب على عشرة فصول : الفصل الأول: توجيهات مختبرية وتعليمات عامة - نموذج كتابة التقريرعن التجربة - التعرف على الأدوات والأجهزة المستخدمة في مختبر الكيمياء ، توضيح الطريقة الصحيحة للتعامل مع الأجهزة ، مبادئ السلامة الأمنية ، مخاطر المواد الكيميائية ، بطاقات التعريف ، قواعد السلامة في تخزين وتداول المواد الكيميائية ،الاشارة الى الإسستعمالات الخاطئة والصحيحة بشكل مخططات او صور او رسوم توضيحية وبعض الإسعافات الأولية . الفصل الثاني: معلومات حول الجدول الدوري للعناصر . الفصل الثالث :الهيدروجين وتجربة (1) وتخص الحوامض والقواعد والأملاح . الفصل الرابع- الفصل العاشر : التجارب من (2-30 ) تخص معلومات عن العناصر بزمر مختلفة مع ذكر المخاطر الكيميائية للمواد الكيميائية التي يتم التعامل معها في المختبر. الملاحق (Appendix ) : وتتضمن بعض الأجوبة النموذجية لبعض تجارب الكيمياء اللأعضوية الواردة في الكتاب مع أسماء جميع عناصرالجدول الدوري وبعض خواصها . الإشارات التحذيرية– إشارات المنع - الإشارات الإجبارية --الإشارات الإستدلالية .
Abstract
The research Compared two methods for estimating fourparametersof the compound exponential Weibull - Poisson distribution which are the maximum likelihood method and the Downhill Simplex algorithm. Depending on two data cases, the first one assumed the original data (Non-polluting), while the second one assumeddata contamination. Simulation experimentswere conducted for different sample sizes and initial values of parameters and under different levels of contamination. Downhill Simplex algorithm was found to be the best method for in the estimation of the parameters, the probability function and the reliability function of the compound distribution in cases of natural and contaminateddata.
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One of the most important phenomenon that occurs in sheet metal forming processes is the spring-back, which causes several geometrical alterations in the parts. The accurate prediction of springback after bending unloading is the key to the tool design, operation control, and precision estimate concerning the part geometry. This study investigated experimentally the effect of pretension in three rolling direction (0, 90, 45 degree) on the springback behavior of the yellow brass, sheet under V shape bending die. The pre-tension ranges from five different levels starting of 11% to 55% from the total strain in each rolling direction by regular increase of 11 %, then bent on a V-die 90 degree for the springback estimate. From experiment the
... Show MoreThe efficiency of Nd:YAG laser radiation in removing debris and smear layer from prepared root
canal walls was studied. Fifty-seven human extracted single rooted anterior teeth were divided into three
groups. A group that was not lased is considered as a control group. The remaining teeth were exposed to
different laser parameters regarding laser energy, repetition rate and exposure time. For the case of the set of
parameters of 7 mJ laser energy, the cleaning was maximum at 3 p.p.s. repetition rate for 3 seconds exposure
time for, the coronal, middle and apical thirds. Above and below this energy level, there was an overdose
(melting) or under dose (no effect). Nevertheless for 10mJ laser energy case, the cleaning effi
Abstract
The government spending in Iraq and witnessed the changes and developments, especially after 2003, which outweighed consumer spending at the expense of capital expenditure and increased support and diversity of trends towards improving pension conditions for member
... Show MoreThat achieve a level of excellence for the quality of university education cannot be achieved only by uniting the efforts of all employees at the university and active participation by students and by alumni and the labor market and society, however we can say that the administrative and academic university staff play an active role and the largest in achieving equivalent quality of higher education, It should unite the efforts of all employees in the educational institution in order to achieve quality education. It is the concept of quality of education, quality assurance and overall management of the quality of the basic pillars on which it is based university education. That highlight the need fo
... Show MoreObjectivity is the common denominator between the qualities and elements of a news story that is described as the mother of journalistic arts. When there is doubt about the authenticity of the information contained in the press, whether readable, audible or visual, it means that there is an imbalance in objectivity. When, furthermore, there is an incorrect and intentional use of words in order to influence readers, it means to move away from objectivity as a necessary element in the success of the media institution; and the success of its editorial material.
But the objective interpretation may take several dimensions to the liaison. For the purpose of grasping the interpretation of objectivity among those liaisons working in the
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Faces of the individual in his life many stressful events, which includes expertise undesirable, and events may involve a lot of sources of tension and the risk factors and threats in all areas of life, and this would make the stressful events play a role in the genesis of many diseases physical.
The high blood pressure is one of the most Actual manifestations of mental stress in the present scale physical disorders which may frequently in men relative to women, which may be caused by spasms in the blood vessels.
The first chapter the importance of research and need for education scientists see that the roots of the use of a specimen Wheatley in learning and teaching back to Grayson Wheatley, one of the largest supporters of a modern construction, which lay the groundwork for the specimen stage and the form in which it is. That was attributed to him, often called his name called while some educators based learning strategy on the issue. He sees the learner in this model make him a meaningful understanding of problems during his progress, thereby acting with his colleagues to find solutions to them in small groups. He
Borders Search: Search by students is determined by th
... Show MoreThe electoral mechanism is remarkably clear, a political tool for institutional construction, directing political life, forming the political scene, and forming the partisan scene. This process was through the design of electoral laws, as elections in Tunisian political history represented the indicator of its slow and accelerated transformations, so The elections in Tunisia usually coincide with important political stages, accompanied by legislative or constitutional amendments in general, Islamic or secular forces have played a fundamental role in promoting the democratic experience and the principle of the peaceful transfer of power. This led to the formation of a national consensus that would help the country not enter into political
... Show MoreOne of the rules concerning the control of civil transactions is the rule of no harm and harm, which was enacted by our Holy Prophet Muhammad (peace be upon him and his family). Scholars singled it out by research and investigation, and classified by non-scientists independent messages, showing the status of al-Qaeda in terms of its perception, meaning, branches and results, and the importance of this rule in the payment of damage and compensation for it has been provided by the Iraqi legislator generous within the provisions of Iraqi law in all its branches of public and private, as applied The judiciary Iraq The provisions of this rule have been issued and numerous decisions have been made to compensate for the damage and to give to ev
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