الخميس، 30 ديسمبر 2021
Measurement tools in the chemical laboratory
الاثنين، 27 ديسمبر 2021
Quality control in laboratory
Quality control
encompasses all activities used to bring a system into statistical control.
The most important facet of quality control is a set of written directives describing all relevant laboratory-specific, technique-specific, sample-specific,method-specific, and protocol specific operations.
Good laboratory practices (GLPs)
describe the general laboratory operations that need to be followed in any analysis. These practices include
1- recording data and maintaining records.
2- using chain-of-custody forms for samples that are submitted for analysis.
3- specifying and purifying chemical reagents.
4- preparing commonly used reagents.
5- cleaning and calibrating glassware.
6- training laboratory personnel.
7- maintaining the laboratory facilities.
8- general laboratory equipment.
Good measurement practices (GMPs)
describe operations specific to a technique. In general, GMPs provide instructions for maintaining, calibrating, and using the equipment and instrumentation that form the basis for a specific technique.
For example, a GMP for a titration describes how to calibrate a buret (if nec essary), how to fill a buret with the titrant, the correct way to read the volume of titrant in the buret, and the correct way to dispense the titrant.
The operations that need to be performed when analyzing a specific analyte in a specific matrix are defined by a standard operations procedure (SOP).
The SOP
describes all steps taken during the analysis, including: how the sample is processed in the laboratory, the analyte’s separation from potential interferents, how the method is standardized, how the analytical signal is measured, how the data are transformed into the desired result, and the quality assessment tools that will be used to maintain quality control. If the laboratory is responsible for sampling, then the SOP will also state how the sample is to be collected and preserved and the nature of any prelaboratory processing.
A SOP may be developed and used by a single laboratory, or it may be a standard procedure approved by an organization such as the American Society for Testing and Materials or the Federal Food and Drug Administration.
Although an SOP provides a written procedure, it is not necessary to follow the procedure exactly as long as any modifications are identified. On the other hand, a protocol for a specific purpose (PSP), which is the most detailed of the written quality control directives, must be followed exactly if the results of the analysis are to be accepted. In many cases the required elements of a PSP are established by the agency sponsoring the analysis. For example, labs working under contract with the Environmental Protection Agency must develop a PSP that addresses such items as sampling and sample custody, frequency of calibration, schedules for the preventive maintenance of equipment and instrumentation, and management of the quality assurance program.
Two additional aspects of a quality control program deserve mention.
The first is the physical inspection of samples, measurements and results by the individuals responsible for collecting and analyzing the samples.
For example, sediment samples might be screened during collection, and samples containing “foreign objects,” such as pieces of metal, be discarded without being analyzed. Samples that are discarded can then be replaced with additional samples. When a sudden change in the performance of an instrument is observed, the analyst may choose to repeat those measurements that might be adversely influenced. The analyst may also decide to reject a result and reanalyze the sample when the result is clearly unreasonable. By identifying samples, measurements, and results that may be subject to gross errors, inspection helps control the quality of an analysis. A final component of a quality control program is the certification of an analyst’s competence to perform the analysis for which he or she is responsible.7 Before an analyst is allowed to perform a new analytical method, he or she may be required to successfully analyze an independent check sample with acceptable accuracy and precision. The check sample should be similar in composition to samples that the analyst will routinely encounter, with a concentration that is 5 to 50 times that of the method’s detection limit.
الخميس، 23 ديسمبر 2021
الخميس، 2 ديسمبر 2021
Relationship between Mass and Wavelength
Relationship between Mass and Wavelength (Elaraby equation)
Ali Elsayed Elaraby
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Abstract
In physics, El araby theory of wave and mass for short, is a scientific
theory regarding Relationship between Mass and Wavelength. the theory is based
on two postulates or two laws
1-
The rest energy is related
to the mass according to the celebrated Einstein equation: E=m*C2
2- Planck explained further that the respective definite unit, E, of energy should be proportional to the respective characteristic oscillation frequency ʋ of the hypothetical oscillator, and he expressed this with the constant of proportionality h : E= h*ʋ
El araby theory
Matter possesses the properties of particles and the properties of waves
by a certain amount that depends on El araby equation , so that the higher the
mass, the lower the wavelength and vice versa in the partial frame
Result
There is an inverse relationship between wavelength λ and mass m
and calculate the proportionality constant K from the theoretically measurements
References
1.
Albert Einstein (2001). Relativity: The Special and the General Theory (Reprint
of 1920 translation by Robert W. Lawson ed.). Routledge. p. 48. ISBN 978-0-415-25384-0.
2. Edwin F. Taylor & John Archibald Wheeler
(1992). Spacetime Physics: Introduction to Special Relativity. W. H. Freeman.
ISBN 978-0-7167-2327-1.
3. Kragh, H. (1999). Quantum Generations. A History
of Physics in the Twentieth Century. Princeton University Press. ISBN
978-0-691-01206-3
4. Kramm, Gerhard; Mölders, N. (2009).
"Planck's Blackbody Radiation Law: Presentation in Different Domains and
Determination of the Related Dimensional Constant". Journal of the
Calcutta Mathematical Society. 5 (1–2): 27–61. arXiv:0901.1863. Bibcode:2009arXiv0901.1863K.
5. Kuhn, T. S. (1978). Black–Body Theory and the
Quantum Discontinuity. Oxford University Press. ISBN 978-0-19-502383-1.
الخميس، 18 نوفمبر 2021
Relationship between Mass and Wavelength ------------------(Araby equation)
(Araby equation) Relationship between Mass and Wavelength
العلاقة بين الطول الموجى و الكتلة (استنتاج رياضي)
على السيد العربى ali alaraby
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نبذة مختصرة
المقدمة
وذلك بالتعويض عن الطاقة من قانون بلانك والتى تعطى قيمة الطاقة بضرب التردد فى ثابت بلانك ʋ E= h*
الاستنتاج الرياضى
1- الطاقة
E 2- الكتلة النسبية (كتلة الفوتون ) m 3- سرعة الضوء C من قانون بلانك E= h* ʋ حيث ان 1-
الطاقة E 2- التردد ʋ 3- ثابت بلانك h (1)(2) من معادلة h* ʋ = m*C2 (3)
العلاقة بين طول الموجة لشعاع
كهرومغناطيسي والتردد هي C =λ * ʋ (4) حيث ان 1- التردد ʋ 2- الطول الموجى λ 3- سرعة الضوء C (3)(4) h* (c / λ) = m * C2 (5) (C)بقسمة المعادلة (5) على سرعة الضوء h / λ= m * C (6) λ * m = h / C حيث
ان K ثابت
ويساوى ثابت بلانك مقسوم على سرعة الضوء K =h / C K(constant) = 6.62607004x10-34/299792458 نستنتج ثابت جديد (ثابت العربى Araby Constant)
لذلك تصبح المعادلة الاخيرة (معادلة العربى Araby equation) Relationship between Mass and Wavelength (Araby equation)
1- الطول الموجى λ 2- الكتلة النسبية m 3- ثابت K |
نتائج البحث
يمكننا طرح نظرية جديدة
نظرية العربى
المادة تمتلك خواص الجسيمات وخواص الموجات بمقدار معين
يتوقف على معادلة العربى بحيث كلما زادت الكتلة قل الطول الموجى والعكس صحيح فى
الاطار الجزئى
الورقة البحثية مجهود شخصى تحتاج مراجعات كثيرة