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Reliability and Validity
Name
Course Title
Institution
Reliability and Validity
Reliability
In the broadest sense, reliability would be looking at the consistency of measurement. The feasibility is observed by measuring the variable several times. Thus, it would be able to prove if the measure is consistent enough (Kothari, 2014). Therefore, a measurement that would be higher is observed to be more reliable than one that would have lower scalability.
Inter-observer reliability is a measure utilizing statistics to address the issue of consistency as a form of measure. Test-retest reliability looks at the consistency level from one period to another (Kothari and Garg, 2014). Reliability can be internal (this would be tested occurring from variables within) or external (this would be tested occurring from outside variables).
Evaluation of interrater reliability would imply that the study uses the same collected results. Thus, the sample would imply a correlation amongst the various sets of variables that have been analyzed. Hence, when all the respondents give a similar value, the test would have higher interrater reliability (Kothari and Garg, 2014). Thus, the aspect of yielding similar results would prove that the test is of the essence and that it is scientific. Therefore, the inferences can be used in the decision-making process and improve the livelihoods of a people.
Test 1
Reliability Statistics
Cronbach’s Alpha N of Items
.066 2
Test 2
Reliability Statistics
Cronbach’s Alpha N of Items
.276 2
Thus, based on the analysis, test 2 is more reliable.
Thus, based on the scientific tools present and used to test for reliability, one would be able to come up with the best measure (Kothari and Garg, 2014). Thus, the repeated analysis would be able to give the best results of a given timeframe over the dataset.
Validity
Validity looks into what will be measured (Kothari and Garg, 2014). This would look at any types of errors that might arise in the questionnaire. For instance, would the variables make sense to the user of the information being used in place.
Internal validity looks at the inferences that carry out the observations amongst the variables to show the type of manipulation if it was done transparently or measured based on the study parameters (Kothari, 2014). External validity looks into the observations that are made based on the manipulation of several variables that would be extending outside.
Concerning the statistical conclusions that are present, the information user would be out to assess the type of analysis. This is whether the data they are getting and the questions they are asking are making sense (Kothari and Garg, 2014). Thus, it would be guided by a psychological framework tasked to improve the nature of analysis and data presentation.
Thus, the study would also have the required sample size. This depends on the statistical test that would be used to analyze the results (Kothari, 2014). Furthermore, the researcher would be keen to look into at least twenty percent of the total population from the total sample size.
For instance, a correlation coefficient at a significance level of 0.05 can be used to analyze. Thus, the result would be testing the significance and insignificance of the variable based on the present results (Kothari and Garg, 2014). Thus, data would form the basis of critique, and the scientists would be able to infer what is happening from the data available for the study.
Thus, the criteria for validity would be based on values 0 and 1.00. This is based on the connection size between the two variables under investigation. This would include variables a and b.
Instrument
Test and measurement
Description
A test and measurement would be used to analyze the strength of the variables based on numerical factors.
Psychometric Properties
It ought to be an accurate system and dependable based on the present analysis.
Psychometric Properties of the Instrument
This will be based on the reliability and validity factors inclined to the correlational coefficients (r = .41).
References
Kothari, C. R., & Garg, G. (2014). Research Methodology: Methods and Techniques. New Delhi:
New Age International Publishers.
Kothari, C. R. (2014). Research Methodology: Methods and Techniques (3rd ed.). New Delhi:
New Age International (P) Limited.
Wadi (Valley) Hanifa History and Geographic
Name
Course Number
Professor’s Name
Date
Wadi (Valley) Hanifa History and Geographic
Introduction
This paper posits to investigate the history and current state of the Wadi Hanifah, also referred to as the Hanifah Valley. The Wadi Hanifa is the most important and longest Wadi (valley) in the vicinity of Riyadh. In the arid region of Najd located in central Saudi Arabia, it is an exceptional natural geographical feature. The Wadi is a natural water drainage route which is fed by numerous offshoots for an area of approximately 4,000 km². It flows to the south-east from the north-west, passing via the western boundaries of Riyadh in its central part. From this central point, the Wadi includes an uninterrupted watercourse due to the every day release of 650,000 cubic meters of raw as well as treated water (Al-Homaidan 25). This uninterrupted water flow has produced a unique phenomenon of all-year around green areas in a scorched environment. Until recent times, sections of Wadi Hanifah, particularly those neighboring Riyadh, had been utilized in a destructive and environmentally disparaging manner. Sections of the Wadi were exploited as dumping grounds for garbage, while other sections were mined for stone or harvesting of sand (Zawahri 4).
As a result, substantial portions of the Wadi have been disfigured and polluted while other sections of its landscape have been extensively altered. The natural water flow in several locations has been blocked, thus producing stagnant pools as well as marshy environments.
Wetlands in the south of the Wadi are principally well-liked for recreational purposes such as fishing, picnics, and swimming. As a result of the wanton degradation of the Wadi, the Higher Commission for the Development of Arriyadh, also referred to as the Arriyadh Development Authority (ADA), carried out comprehensive studies of Wadi Hanifah. The rationale of the study was to develop a strategy for the rehabilitation of the wadi (Vidal 6).
CONTEXTUAL INFORMATION
Climatic Conditions. Rainfall in this area is quite limited and averages at approximately 85mm annually. Over 50% of that amount comes about in March and April. The temperatures in the Riyadh region range from 6.4°C on average in January to 42.9°C on average in July.
The Historical Background. The Wadi Hanifah is of significant historical value. It derives its name from the people of Bani Hanifah, who inhabited the Wadi at some point in the 5th century AD. The wadi is a substantial productive strip that in the past served as an agricultural hub, supporting human settlements in its vicinity. The Wadi Hanifa It also holds a big number of heritage sites that include human settlements, defensive towers and walls, as well as dams. Several of the historical structures in the Wadi are built of sun-dried mud bricks, although locally mined stone is also extensively utilized. Among the most significant heritage sites found in the Wadi is Al Dir’iyyah, the native land of Al Sa’ud, the Saudi Arabian royal family (Wilhite 59).
Site and Surroundings. The Wadi Hanifah extends for approximately 120 km in length. It has a depth that varies from 10 to 100 meters and its breadth varies from 100 meters to 1 km at its widest fringes. It offers a natural drainage route for over 4,000 m² of open area found along its span. A series of approximately forty smaller offshoots, referred to as sha’ibs, drain their water into the Wadi Hanifah and these tributaries can be approximately 25 km long. These tributaries include, Wabir,
Al Ubaytah, Safar, Al ‘Ammariyyah, Al Mahdiyya, Laban, Al Awsat, Laha, and Nammar. The tributaries located at the eastern side include Batha’, and Al Aysan. In cross-section the deepest part of the Wadi is located in the centre. This is where the watercourse is positioned. This is surrounded on both sides by a level area typified by deposits of clay soil as a result of flooding in the Wadi and able to sustain several agricultural as well as grazing activities. The level areas are broader in the middle and northern parts than in the southern parts (Kassas 125).
State of the Wadi Before and After Contamination. The Wadi Hanifah is segmented into five zones by its development strategy plan. The five zones are based on disparities in the ecosystem and levels of latest exploitation and resultant environmental degradation. The two least developed sections of the Wadi are located at the north of Riyadh. These sections comprise of several traditional settlements as well as farmlands. The traditional city of Al Dir’iyyah is found in this area (Philby 62). These zones are generally well utilized and have not been degraded as other sections parts of the Wadi. The most prevalent forms of degradation in the Wadi result from mining, dumping, as well as pollution. In these two zones primarily hold private farms which are not subjected to the contaminated water that drains into the Wadi further south. Their comparative distance from Riyadh also plays a considerable function in this regard (Danhof 62).
The third zone crosses through the western sections of Riyadh. The urban part of the Wadi expands from the Al ‘Ilb dam in the north to the region of Al Masani’ in the south. This is the most degraded section of the Wadi due to the numerous environmentally disparaging activities that occur in this region. Quarrying and dumping are the most prevalent in this region as a result of the establishment of a variety of light manufacturing projects (Philby 65). The prevalence of a variety of unrestrained construction activities, as well as the discharge of contaminated water into the Wadi also contributes immensely to the environmental degradation of the Wadi.
The fourth and fifth zones expand southwards from the region of Al Masani’. Although less contaminated than the third zone, this fourth zone however, suffers from the release of contaminated water, which results from numerous activities, including the tannery. The fifth zone expands from Al Ha’ir dam, which has a holding capacity of two million cubic meters, to the end of the Wadi. This zone is also referred to as the ‘Lakes Area’. This part of the Wadi receives an uninterrupted release of water. Since the building of the Al Manfuha treatment station, the primary water treatment plant in Riyadh, approximately two-thirds of the released water in the Wadi has been treated to tertiary degrees. Water that is untreated water also finds its way into the Wadi. Nevertheless, by the time the water reaches the fifth zone, it is comparatively well filtered and a substantial amount of its organic dissipate has been removed by means of natural oxygenation processes. The reed beds that grow along the waterway supply physical filtering and hence oxygenate the water (Murray 109).
On the other hand, in the fourth and fifth zones, there are issues of water stagnation as well as the resultant creation of swampy conditions. The region ends in a sequence of substantial interlinked lakes. A diversity of paved and unpaved infrastructure crisscrosses the Wadi. A number of the roads are used as throughways linking areas alongside the two parts of the Wadi. The comparatively high level of traffic in the Wadi has resulted in problems that relate to air pollution. A variety of vehicle lubricants are poorly disposed of, particularly in the central section of the Wadi. The Wadi has incredible prospects as a recreational space for Riyadh people. In effect, the southern sections of the Wadi are quite popular with picnics. Regrettably, no services are offered for the people who go out for picnics in the Wadi. There is also the absence of regulation regarding issues like cleanliness and hygiene and sections of the Wadi, particularly in the south, demonstrate the impact of heavy littering from persons who utilize the Wadi for picnics (Homer 62).
The Wadi Hanifah Development Project. The wide-ranging development plan consisted of five interlinked components. The first was environmental classification. This constituent aimed at establishing the ecological characteristics of the diverse zones of the Wadi. It provided mechanisms that would ascertain the Wadi’s ecological sustainability, and create a structure for positive and sustainable interface between the Wadi and the Riyadh city (United Nations Development Program 20). The second component emphasized issues that relate to management of water-demand. The release of water into the Wadi is projected to increase from the present 650,000 m³per day to 2,000,000 m³ per day in the next two decades. This component of the project aims to address the problem of the rising amount of contaminated water being released into Wadi Hanifa. This is from diverse sources such as the slaughterhouse and the tannery. The management of water-demand would offer answers to the problems of swampy conditions. Additionally this component focuses on implementation of natural oxygenation processes for the water that passes through the Wadi (Haddadin 4).
The third constituent of the plan included putting in place efficient land-use plans. The objective was to end improper and contaminating land utilization such as mining, dumping as well as industrial activities that discharged contaminated water into the Wadi. This component also dealt with the severe and chronic problem of private encroachment on public land in the Wadi (Amery 3). The project would allow recreational, agricultural, touristic and residential utilization, as long as these do not cause environmental degradation. In addition, significant sections of the Wadi would be confirmed secluded historical or natural zones (Wenche 90).
The fourth constituent of the plan concentrated on rehabilitating the Wadi and rehabilitating its previous ecological balance. This included execution of physical works like clearing sections that were subjected to dumping as well as filling up open quarries. This constituent would also put into operation the redesigning of the infrastructure in the Wadi in order to eradicate air pollution from automobiles and minimize several other harmful environmental impacts (Wolf 51).
The fifth component of the project dealt with the issue of regulating development in the Wadi. This included implementing a monitoring program that would follow up on the environmental effects of the activities that occur in the Wadi. It would also monitor the water quality in the Wadi. This component of the project offers a check and balance system for the different other components in the project (Al-Nuaim 5).
CONCLUSION
The Wadi provides several opportunities. It offers a spectacular and substantial green area that comprises of several heritage sites. It has prospects of offering high-quality and reachable recreational, cultural, touristic as well as environmentally preserved regions that may serve the population of Riyadh and tourists from other places. If sustainable development policies are implemented, the resultant arrangement would significantly improve the Riyadh’s quality of life. The Wadi has the ability to sustain income generating activities that would relate to recreation and tourism. This would provide numerous employment opportunities for the population. It would also sustain considerable agricultural activities, which would provide income streams and food. It is noteworthy that there is a need to shield the Wadi agricultural regions from urban sprawl.
Works Cited
Al-Homaidan, S. Water Chemistry & Algal Vegetation in Saudi Arabian Reservoirs. IA: Iowa University Press, 2009. Print.
Al-Nuaim, M. Profile of the Contemporary Development of Riyadh. Royal Embassy of Saudi Arabia. 2 (2010): 5. Print.
Amery, H. Water Conflicts in the Middle East: Looming Threats. The Geographical Journal. 45 (2010).3. Print.
Danhof, C. Revolutionizing Agriculture: The Agricultural Press. N.Y: Columbia Press, 2004. Print.
Haddadin, F. Water & the Peace Process. Geographical Journals. 168 (2009):4. Print.
Homer, T. Environment, Scarcity, & Violence. Princeton: Princeton UP, 2009. Print.
Kassas, M. Ecology & Desertification Management: Geographic Perspectives. 29 (2009): 125. Print.
Murray, R. Rivers of Fire: The clash over Water in the Middle East. Lanham: Rowman & Littlefield. 2010. Print.
Philby, W. Southern Najd. Geographical Journals. 45 (2010): 62–65. Print.
United Nations Development Program. Human Development Reports 2009: Poverty, Power & the Global Water Crisis. N.Y: Palgrave, 2009. Print.
Vidal, P. What the Arab World Does When Its Water Dries Out: The Observer.23 (2011): 6. Print.
Wenche, E. Casual Trails to Conflict. Boulder: Westview Press, 2010. Print.
Wilhite, S. Understanding Drought Phenomenon. Lanham: Rowman & Littlefield. 2010. Print.
Wolf, A. Conflict & Cooperation in Global Waterways. Water Policies. 1 (2010): 51. Print.
Zawahri, M. Stabilizing Riyadh’s Water Supply: Third World Quarterly. 45(2010): 4. Print.
O2 Transfer in Human Body
Name
Course Instructor
Course
Date
O2 Transfer in Human Body
Oxygen (O2) is a significant element in the human body that plays a crucial role of sustaining life and enhancing metabolic process in human body. Despite life sustenance, oxygen helps in terminating destructive bacteria that human body does not need and leaves the important bacteria in human life safe. Chemical engineering treats human body as a chemical plant with air acting as both input and output to ensure smooth operation. There are also other input including food and water as well as other output such as feces and urine. In addition, complete circulation of oxygen requires pumping mechanism in the human body that involves two important organs, the heart, and the blood vessels. Chemical engineering treats circularly system as a chemical process that involves the heart as a pump while the blood vessels act as passageways for oxygen. Generally, chemical engineering uses mathematical equation to show a complete oxygen transportation process in the body. Moreover, chemical engineering involves two basic terms including convection and diffusion that helps in calculating oxygen transport in the human body. Convection is more common in the large blood vessels like arteries while diffusion is more likely to occur in the small blood vessels such as capillaries and veins.
The two main mathematical equations involved in determining oxygen transport are the overall flux that describes oxygen flow via pipes and Fick’s law that explains diffusion of fluid along a concentration gradient.
The overall flux
NA,z = YA ( NA,Z + NB,Z ) – DA,T∇c
Convection Diffusion
Fick’s law
JA,z = −DA,z∇c
Describing Oxygen Transport in Human Body
Oxygen moves in the human body in the breathing process through nose and mouth then goes via the lungs and dissolves in the water lining of alveoli. Oxygen then sticks to red blood cells while passing through the alveoli capillaries.
Circulatory System
Circulatory system plays a significant role in transporting various materials in the human body. Circulatory system ensures that nutrients, water and oxygen are transported to the body cells while transporting waste products produced by body cells such as carbon dioxide away from the body. The circulatory system acts as a highway with network throughout the human body and it involves the heart, and the blood vessel. The heart is responsible in pumping blood and maintaining blood flow in the whole of the body system while the blood vessels transport blood away from the heart to other parts of the blood. The whole of the circulatory system transports oxygen from outside the body into the blood stream and carries away waste from the blood cell, carbon dioxide to the outer part of the body.
The Blood Vessels
The blood vessels function as pathways in the human body through which the blood travels. Blood vessels include the arteries, veins, and capillaries that have distinct functions. The arteries carry blood away from the heart while the capillaries link arteries with veins as veins transports the blood back to the heart during blood circulation process. Initially, the heart usually pumps blood through the arteries (dorsal aorta) before arteries supply the blood to smaller arteries in ensuring that everybody cell receives oxygenated blood. Veins however receive blood from the capillaries after the blood has exchanged the two important gases, oxygen, and carbon dioxide and transports the waste rich blood back to the circulatory organs, lungs and the heart. Capillaries play a significant role of linking arteries with veins and further carry oxygenated blood to the other body parts thus enriching the tissues with oxygen. There are also thin capillary walls that provide a surface area for gaseous exchange by letting the red blood cells inside the capillaries to release oxygen to other surrounding tissues as the tissues release their waste products such as carbon dioxide that is absorbed in the red blood cells.
The Blood
The blood is a very significant substance in the human body system and in the circulatory system because it transports oxygen that is helpful in the life of the body tissues and helps in releasing carbon dioxide, which is harmful to the tissues. For a human being to be alive, the human tissues must receive oxygen, which is transported by the blood. Blood also carries very vital elements in the human body that include the red blood cells, water, oxygen, nutrients and waste products that provide life to the body cells. The blood transfers oxygen to the body tissues after taking it from the lungs and aids the tissues by carrying their waste, carbon dioxide from the tissues to the lungs.
The red blood cells continuously run throughout the body by transferring oxygen to the body tissues and carrying carbon dioxide out of the tissues to the lungs. The red blood cells normally take oxygen from the lungs and releasing it by pressing its way through the body with the aid of capillaries. It is normally made up with a chemical known as hemoglobin, which is rich in iron that attracts oxygen to the red blood cells. Usually, as the blood moves through the lungs, oxygen molecules are attracted to the hemoglobin but as the blood goes through the tissues, it releases oxygen to the cells. Finally, after releasing oxygen to the body tissues, the oxygen-less hemoglobin combines with the tissues’ waste such as carbon dioxide and transports them away from the tissues back to the lungs. Nevertheless, plasma, a thick container that carries the red blood cells, usually occupies 55% of the blood capacity and it is composed of nutrients, waste products and the clotting protein.
Diffusivity: DA, B
Diffusion coefficient is a function that relies on the size and atomic component of the diffusing substances and the characteristics of the means. Tiny molecules easily go through biological system such as oxygen because they have higher diffusivity while bigger particles slowly pass through because they have lower diffusivity. Additionally, some medium with heavy or denser tissues experience little diffusion coefficient while less denser medium have higher diffusion coefficient.
Convection and Diffusion
Conviction had been earlier defined as the transfer of bulk material sandwiched between border surface and moving fluid while diffusion is the act of net motion of molecules in the path of lower concentration. Conviction is mainly evident in the larger blood vessels while diffusion mostly takes place in the small blood vessels. Nevertheless, looking at the overall flux equation based on conviction, what is normally considered is the rate at which oxygen flows because of flowing blood hence shown in the direction of the blood flow.
NA,z = CA + VA,z
By considering the conviction, the oxygen concentration within the blood vessels is regarded as constant as the small vessel oxygen moves out of the veins and to other neighboring tissues thus reducing the concentration. It is also worth noting that diffusion is quicker outside the capillary walls that normally have concentration profile. Additionally, convection usually occurs within the vessel whose concentration of dissolved oxygen presumed constant.
NA,z = YA ( NA,Z + NB,Z ) – DA,z∇c
Importantly, normally while the vessels reduces in diameter, convection’s dominance also reduces thus triggering a significant increase in diffusion.
Bio-hybrid Devices
Bio-hybrid devices is an artificial mechanism used in substituting tasks of damaged organs through amalgamation of cells with manmade constituents (polymer) so that they can discharge proteins that are regarded useful for the operation of particular organs. These devices further aid in defending organs from being damaged by the recipient immune system. Moreover, the devices may be explained as what enables the body to interchange and take the implant cells without denunciation from the immune system.
These devices may be helpful in averting various diseases such as diabetes. In the case of diabetes, especially amongst the genetically predisposed individuals, a device called artificial pancreas may remedy numerous challenges involving replacement of insulin that produces tissue in diabetic patients. Moreover, in the case of liver failure, the biohybrid artificial liver (BAL) which is an extracorporeal supportive device may represent a significant therapeutic strategy for people suffering from liver failure. The BAL system is composed of working liver cells that are aided by a synthetic cell culture substance and therefore serves as a link for the patients before a donor organ is provided or the liver is redeveloped.
Biohybrid consist of both intravascular and extravascular where intravascular are inserted within the large blood vessels while the cells are put outside the blood source. In the case of intravascular biohybrid device, oxygen moves from the capillaries to the tissues. On the other hand, there are extravascular biohybrid device that are put on the external part of the vascular section while the cells are condensed in tissue that is encircled with red blood cells. This provides a significant role of stimulating blood vessel growth hence permitting sufficient oxygen mass movement within the device.
Works Cited
Dorian, AI; 2009. The development of bio-articial organs. Medical Research Reviews 2009; 28(2):187-252-296
Jean Krudener, “circulatory system,” in Hillendale Health, web:02/25/2012 <http://hes.ucfsd.org/gclaypo/circulatorysys.html>
Lucy P , Hugye D, Vazeou P, Gentile T, Danne K,2010. Maintenance of narmoglycmia by biohybrid device. Science 2010; 254:1786-1784
Provost P ,2010, Application of CN79 hydrogel in Bioyhybrid encapsulation: mathematical model.
Transplant Proc 2010; 27:274493-3895
