Token Economies Have A Long History Of Being Identified As...

Token economies have a long history of being identified as evidence based practice (Simonsen, Fairbanks, Briesch, Myers, Sugai, 2008). Through the use of positive reinforcement and negative reinforcement, token economies function to manage student behaviors. Such economies are widely used in classrooms, especially in special education classrooms that tend to have students with more severe behavior problems. According to Cooper, Heron, and Heward (2007) significant research has demonstrated the effectiveness of the token economy as a means to change behavior. As previously stated, token economies rely on principles of positive reinforcement to increase the occurrence of target behaviors through the delivery of a token. Tokens can†¦show more content†¦The token economy was selected based on the fact that is uses many of the core principles of applied behavior analysis such as positive reinforcement. It was also selected based on its history of strong empirical evidence that s upports the effectiveness of such a behavior change system. A multiple stimuli without replacement (MSWO) preference assessment was conducted to identify tangible reinforcers to use as part of the token system as a means to reduce undesired student behavior. According to Daly, Wells, Swanger-Gagnà ©, Carr, Kunz, and Taylor (2009), multiple-stimulus without replacement (MSWO) preference assessments are helpful for identifying preferred common classroom activities as reinforcers with children with behavioral disorders. Using an MSWO, Daly et al. (2009) identified and used high, medium, and low preferred stimulus contingent on the completion of math problems. The researchers reported a high correlation between the preference ranking and number of problems the students completed. For this study, the MSWO assessment will be conducted over the course of three consecutive days. For a selected item to be ranked as preferred, it must be selected in at least 80% of opportunities (Tarbox, Ghezzi, Wilson, 2006). Literature Review According to Matson and Boisjoli (2009), token economies have been commonly used to support the improvement of target behaviors such as attention seeking and task avoidance behaviors. Token

Esr Experiment Free Essays

string(86) " may be introduced in the ampli\? cation stages of the spectrometer and oscilloscope\." Electron Spin Resonance Tabish September 2003 Aim: To determine the Land? g-factor using Electron Spin Resonance. e Apparatus: ESR setup which includes Helmholtz coils, R. F. We will write a custom essay sample on Esr Experiment or any similar topic only for you Order Now oscillator and the test sample, and in addition, a cathode ray oscilloscope (CRO). Theory Background Suppose a particle having a magnetic moment  µ is placed in a uniform magnetic ? eld of intensity B, then the Hamiltonian can be written as ? H=g e ? J  · B, 2mc where g is the Land? g-factor, which is 1 for orbital angular momentum, and 2 for spin angular e e? h momentum. The factor 2mc , sometimes written as  µB , is called Bohr magneton, if the particle in question is an electron. If the particle is a nucleon, then the factor is called the nuclear magneton. If the angular momentum J results from a combination of an orbital angular momentum and a spin, then g would be given by the Land? formula: e g =1+ j(j + 1) + s(s + 1) ? l(l + 1) , 2j(j + 1) where l, s and j represent the magnitude of the orbital, the spin and the total angular momenta, respectively. Remember that j can go from l ? s to l + s. Conventionally, the static magnetic ? eld is assumed to be pointing along the z? xis, which modi? es the above equation to e ? ? Jz B. H=g 2mc Let us now consider an atom which has an electronic ground state with total angular momentum j = 1/2 and an excited state with j = 3/2 (see ? gure 2). There is only a single transition which can be induced by the absorption of radiation of frequency ? 12 = (E2 ? E1 )/? . As the energy does not depend h on the angul ar momentum states, the ground state is doubly degenerate corresponding to eigenvalues  ±1/2 ? of Jz and the excited state is quadruply degenerate corresponding to eigenvalues +3/2, 1/2, ? 1/2, ? 3/2 of ? Jz . 1 Electronic excited state Electronic transition j=3/2 ESR Electronic ground state j=1/2 ESR Zeeman effect If one now applies a magnetic ? eld B along the z-axis, each of the angular momentum states acquires a di? erent energy. The ground state energy level thus splits into two sublevels and the excited state level into four sublevels. This is called Zeeman splitting. Now instead of a single transition of frequency ? 12 = (E2 ? E1 )/? , many transitions of frequencies close to ? 12 h are possible. Experimentally this is seen as a splitting a single absorption or emission line into several closely spaced lines. This is called Zeeman e? ect. As one would have noticed, transition should also be possible between the sublevels of the same energy level. It is indeed possible and this phenomenon is known as electron spin resonance (ESR). Electron Spin Resonance Let us try to understand the phenomenon of ESR in somewhat more detail. As ESR invloves transitions only between the sublevels of one energy level, we will not bother about the Hamiltonian of the atom/molecule which gives us the energy levels. We will only worry about the part of the Hamiltonian which is the result of the applied magnetic ? ld B, which gives us the sublevels. For simplicity, we will consider one electron with angular momentum j, in a magnetic ? eld B. In addition we have an electromagnetic ? eld of frequency ? in the direction perpendicular to B. The time-dependent Hamiltonian can thus be written as ? H=g eB ? ? ? Jz + V0 ei? t + V0†  e? i? t , 2mc ? where V0 represents the interaction of the electromagnetic ? eld wit h the electron. The electromagnetic ? eld is supposed to be very weak compared to the applied static ? eld B, and so one can use time-dependent perturbation theory to study this problem. The states ? hat we will use are the eigenstates of Jz : ? Jz |m = hm|m , ? where m will take 2j + 1 values, from ? j to +j. The energy of these levels is given by g where n eB ? Jz |n = 2mc n |n , = geB? n h 2mc = gB µB n. In time-dependent perturbation theory, we know that the time-dependent interaction can cause transition between various |m states. The transition rate per unit time, from i th level to j’th level is given by: 2? ? Wij = | j|V0 |i |2 ? ( j ? i ? h? ), ? h ? assuming that j i . This expression says that transition from state |i to |j is possible when the frequency of radiation ? ( j ? i )/? . This is the condition for resonance, or in our case, h electron spin resonance. ? ? There is one important point about the form of V0 . It happens to be such that j|V0 |i is nonzero only when j = i  ± 1. This means that transition is possible between, say, | ? 3/2 and | ? 1/2 , but not between, say, | ? 3/2 and |1/2 . Such restrtictions, imposed by the kind of interaction and the nature of states, are called selection rules. 2 The ESR setup Description of the ESR Spectrometer A block diagram of the ESR Spectrometer is given in the ? gure above. Basic circuit The ? st stage of the ESR circuit consists of a critically adjusted radio frequency oscillator. This type of oscillator is required here, so that the slightest increase in its load decreases the amplitude of oscillation to an appreciable extent. The sample is kept inside the tank coil of the oscillator, which in turn, is placed in the 50 Hz magnetic ? eld generated by the Helmholtz coils. At resonance, i. e. when the frequency of oscillation becomes equal to frequency corresponding to the energy splitting of the sublevels, the oscillator amplitude registers a dip due to the absorption of power by the samp le. This obviously, occurs periodically four times in each complete cycle of the supply voltage of the magnetic ? eld. The result is an amplitude modulated carrier which is then detected using a diode detector and ampli? ed by a chain of three low noise, high gain audio-frequency ampli? ers to suit the input requirement of any oscilloscope. Highly stabilized and almost ripple free power supply for the above circuit is obtained using an integrated circuit regulator. Phase shifter This can compensate the undermined phase di? erence which may be introduced in the ampli? cation stages of the spectrometer and oscilloscope. You read "Esr Experiment" in category "Papers" 0 Hz sweep unit A 50 Hz current ? ows through Helmholtz coils which provides a low frequency magnetic ? eld to the sample. As the resonance is observed at a few gauss only, no static magnetic ? eld is applied. R. F. Oscillator It is a transistorised radio frequency oscillator suitable for the determination of resonance frequenc y. Frequency range: 10 MHz to 18 MHz Accuracy: Better than 0. 5 % The Sample The sample used in our ESR setup is diphenyl-picryl-hydrazyl (DPPH). It is a widely used standard in ESR experiments. The structure of this organic molecule, shown in the ? gure, contains three benzene rings. Its important feature is that it contains a single unpaired electron, whose orbital angular momentum is 3 O2N N N NO2 O2N zero. So, the electron has only the spin angular momentum, and the material gives a g? factor which is close to 2. 0038. One thus has to deal with the simple situation where j = 1/2, and only two sublevels are involved. In conventional spectroscopy, absorption intensity is plotted against the frequency of radiation to get the absorption spectrum. In the present case, one should obtain a single abosorption geB peak at frequency ? = ( j ? i )/? , which is nothing but ? = 2mc . However, in this setup it is h di? ult to vary the frequency of radiation. So, what is done is that the frequency of radiation is ? xed at some ? 0 , and the normally static, magnetic ? eld is swept between the positive and negative extremes of a maximum ? eld value. This is done by supplying an alternating current to the Helmholts coils which are supposed to generate the magnetic ? eld. Durin g the AC cycle, 2mc whenever the strength of the magnetic ? eld (+ve or -ve) becomes equal to B0 = ? 0ge , there is a resonance condition, and radiation is absorbed. Origin of four peaks In this experiment, the CRO is used in the x-y mode. The signal from the AC source, which supplies current for the magnetic ? eld, is fed to the X plates of the CRO, and the absorption signal is B fed to the Y plates. The point on the extreme right on the CRO 2 4 3 1 screen represents the maximum positive value of the ? eld, and the point on the extreme left represents the maximum negative value ? B of the ? eld. The point at the center represents zero ? eld. Without Time the Y-plates, the point on the CRO screen goes from maximum negative value to zero, and the maximum positive value, and then back again to the mimimum value. As one can see from the ? gure, the ? eld strength becomes B0 four times in one single sweep cycle. 0 0 0 Now if the absorption signal is fed to the Y-plates, whenever the ? eld strength becomes B0 , the Y-axis will show a peak. So, one should see four peaks corresponding to points 1,2,3,4 in the ? gure. But one can see that on the X-axis of the CRO screen, points 2 and 3 are the same, because they correspond to the same value of the ? eld B0 , and points 1 and 4 are the same because they correspond to the ? eld ? B0 . So, the four peaks should overlap such that only two are visible. However, the absorption signal passes through some electronic circuitry before being fed to the Y-plates of the CRO, so it very di? cult to make sure that no phase change occurs in the process. If there is a small phase di? erence between the AC signal on the X plates and the signal on the Y plates, when points 3 and 4 are traced, the peaks do not overlap with those at 1 and 2. So, in practice one would see four peaks. If one has a way of changing the phase of, say, the Y signal, one can adjust the phase manually so that the four peaks merge into two. Getting the numbers We have the control over the current that is passing through the Helmholtz coils, and this can also be measured. But what we actually need for our calculation is, the magnetic ? eld B applied to the sample. Let us ? rst calculate the magnetic ? eld through the Helmholtz coils. This can be done easily 4 using the Biot-Savart law. B =  µ0 4 5 3/2 I N , r where:  µ0 = 4? ? 10? 1 (cgs units) N = number of turns in each coil. r = the radius of the Helmholtz coils in cm (which is equal to their separation when they are properly arranged). I = current passing through the coils. The value of B is obtained in gauss. As the current is measured by an AC ammeter, the value of the current, and thus the ? eld, is the r. m. s. value. The peak value of the ? eld will be given by v v 8 2 I N . Bmax = 2B =  µ0 v 125 r Suppose the peak value of the ? eld (= Bmax ) corresponds to P divisions from the center on the x-axis of the CRO screen. Then if Q be the distance of the observed resonances from the center (in the units of divisions), the ? eld corresponding to the resonance will be given by: B0 = Q But the resonance condition is given by: B0 = h ? 0 ? , g µB Bmax P hich can be used to determine the value of g, once B0 is known. Now, for a ? xed ? 0 , B0 is ? xed, although one can vary the current I and get various position of the absorption peaks. Let us write the expression for B0 and see what is most accurate way to calculate it: v N  µ0 8 2 v B0 = I  · Q. rP 125 The ESR spectrometer is such that P does not vary as one varies I. So, the best way to evaluate the above expression will be to plot a graph between 1/I and Q, and ? nd out the slope, which will give the average value of I  · Q. The ? eld at the absorption peaks can be calulated as: v N  µ0 8 2 v B0 = ? lope of graph between 1/I and Q. rP 125 Procedure Connections Connections are done as follows: †¢ ESR spectrometer and power supply are connected with connecting cables. †¢ Connect the coaxial cable of the induction coil to the oscillator through the socket marked â€Å"input†. 5 †¢ Connect the Helmoltz coils to the power supply terminal marked â€Å"H† coil. †¢ Connect the â€Å"Out-put† terminal marked X, Y, E on the ESR spectrometer to the X plate, Y plate input and ground of the oscilloscope respectively and switch on the oscilloscope. †¢ Connect the power supply with AC mains. Adjustments Adjust the current in the Helmholtz coils at 150 mA. The front panel controls of the ESR spectrometer are adjusted as follows: frequency, detector and phase, all centered. Experimental procedure The X plate of the CRO is callibrated in terms of magentic ? eld as follows: 1. X ampli? er of the CRO is adjusted to obtain the maximum X de? ection (e. g. P divisions. 2. Note the current ? owing in the Helmholtz coils. The magnetic ? eld can then be calculated from the formula for B given before. Number of turn in the coils N = 500 and the radius r = 7. 7cm. The positions of the two peaks of the ESR signal at resonance is measured. Let this be Q divisions from the center. The best possible resonance peaks are obtained by varying the frequency in the range of 12 to 14 MHz and the Y sensitivity of the oscilloscope. The pahse knob is adjusted to coincide one pair of peaks with the other. The current through the coils is then varied, keeping the frequency ? xed, and the corresponding position of the peaks from the center noted. A graph between 1/I and Q is then plotted and can be used in calculating the g-factor, as described earlier. Repeat the above procedure for di? erent values of frequency. Observations and calculation S. No. 1. 2. 3. 4. 5. 6. I(mA) 150 175 200 225 250 275 I(A) 1/I Distance of peaks from center (Q) 10 MHz 13 MHz 15 MHz 17 MHz 2. 4 1. 9 1. 9 1. 9 2. 0 1. 6 1. 6 1. 5 1. 4 1. 4 1. 4 1. 4 1. 2 1. 3 1. 2 1. 2 1. 1 1. 1 1. 1 1. 0 1. 0 1. 0 1. 0 1. 0 0. 150 6. 667 0. 175 5. 714 0. 200 5. 00 0. 225 4. 44 0. 250 4. 00 0. 275 2. 636 Slope of the graph (= I  · Q) = 0. 282, P = 5, N = 500 r = 7. 7cm,  µ0 = 0. 1 ? 4? ,  µB = 9. 2741 ? 10? 21 , h = 6. 626 ? 10? 27 . v N  µ0 8 2 v B0 = I  ·Q rP 125 v 500 ? . 1 ? 4? 8 2 v ? 0. 282 = 7. 7 ? 5 125 = 4. 657 6 ?0 = 13 MHz 2 1. 8 1. 6 Q 1. 4 1. 2 1 0. 8 3. 5 4 4. 5 5 1/I 5. 5 6 6. 5 7 g = h? 0  µB B 0 6. 626 ? 10? 27 ? 13 ? 106 = 9. 2741 ? 10? 21 4. 657 = 1. 9944 Precautions 1. The direction of the Helmholtz coils should be preferable adjusted so that the ? eld is perpendicular to earth’s magnetic ? eld, which is about 0. 3 Gauss. 2. Setup the experiment at a place free from electric and magnetic ? elds and mechanical disturbances. 3. Y-output from the ESR spectrometer should be through a good shielded cable. 7 How to cite Esr Experiment, Papers

Physical Distribution and Logistics Method

Question: Discuss about the Physical Distribution and Logistics Method. Answer: Introduction A distribution channel is a path on a way through which goods and services move until it reaches the consumer. Distribution channels are of different length. Some of the distribution channels can be short such as direct transactions from the producer to the consumer while others can be long involving many other intermediaries like retailers, distributors or wholesalers, agents among others. Distribution systems where the goods or services reaches the consumer without any middleman are called direct distribution, while in cases where the goods or services leave the producer but passes through intermediaries before reaching the consumer are called indirect systems. Distribution can also be said to be business-to-business distribution when one business interacts with another to carry out commercial business or can be business-to-consumer distribution when the producer transacts with the consumer (Krause 2007, pp 528-545). There are many challenges that face distribution channels. Some of these problems are major while others are minor. Examples of the significant operational challenges faced by these distribution channels include market regulations for different goods and services, the effects of labor conditions for various markets in the world, the cost of managing the various distribution channels among many others. Every business organization should work to understand and have a way to regulate or curb these problems for the smooth business operation. Failure to have an established strategy to handle these challenges will reduce the profitability of the organization and therefore reduce organizations competitive advantage (Partridge, 2010). Cost as a challenge faced by distribution channel Many business groups have come to a realization that most of the traditional distribution channels are not working for them, mostly because these channels have become so costly to the companies. In addition, these traditional approaches have added very little value to the business enterprise. Therefore, they neither meet most of the needs of the customers nor handle the manufacturers needs and expectations. This reduces the business profitability and reduces its competitive advantage of these business organizations (Baird et al. 2011). Reduction of the distribution channel cost is an important aspect of consideration for every business organization. They should, therefore, look for ways to achieve this. Organizations should be vigilant enough to identify and innovatively use the possible available channel options that are cost effective to the business group (Gartner 2013a). Use of the traditional distribution channel approaches has become obsolete, and an organization which does not explore new innovative options for the channel distribution is likely to lose its competitive advantage. It is, therefore, clear that every manufacture needs a fresh new template guide to lead them through exploring of the available distribution channel options (Dittmann 2012). Many business organizations have been presented with distribution channels coming as complete distribution channel packages. Businesses, therefore, have options to choose the package that seems appropriate to them in consideration of the firm situational factors. The options can be direct sales to the consumers, use of manufacturers representatives in the distribution channel, use of wholesalers and distributors, and even the retailers among others (Sweeney 2011, pp 30-48). Every package operates in a different way, and therefore business organizations always evaluate the most appropriate package depending on the context of the operation, the industry itself, the situation among other factors. There have been little possibilities for the organizations to make changes in the existing distribution channel packages. This has therefore made business organizations to consider traditional approaches perfect and have not made enough efforts to understand and evaluate the distribution channe l costs and value derived out of it (Stock Boyer 2009, pp 690711). The best way to evaluate the cost and value brought to the business organization by any distribution channel option is through a keen identification of the activities done by a given particular channel, find out the costs of performing activities and then comparing those actions with the values and needs of the consumer (Bradley 2013, pp 10051022). This will, therefore, help the manufacturers to be able to compare the kind of activities performed by an individual channel, the amount of cost incurred and see the value derived out of it. With this evaluation, the manufacturers will be able to identify the best channels that are efficient and cost effective o the organizations. How to reduce cost of distribution channels Every organization that wants to get more profit will always try to cut down the costs. Cost reduction in distribution channels lies around quality and process improvement. This is the only sure way of reducing the expenses incurred in the distribution process (Lawson 2008, pp 446-460). Every business organizations management should not view their company to be composed of organization units or solid entities like marketing unit or sales unit etc., but rather the management should narrow down up to the level of identifying the various activities performed by each unit. This is an inevitable and crucial step in quality and process improvement (Nike 2013). Given the fact that organizations management only gets packages of distribution channels available for them to choose from, identification and analysis of each activity performed by various specific units in an organization is a crucial aspect of consideration. This is because it brings an understanding of the best distribution channel to use regarding efficiency, cost-effectiveness, and value derived from the channel. This, in turn, becomes very useful for the organizations to choose the best channel to use for distribution in a cost-effective way (Coyle 2013). Narrowing down from the organizations subunits means that the organizations management establishes all the activities performed by each unit in the distribution. This will help them to come to an understanding of what is done on the ground and also be able to identify the specific party responsible for performing each particular activity. With this understanding, the company will be able to compare the value derived from each specific activity in comparison to the cost incurred for those activities. With so doing, the company will be able to reduce these costs by smoothening the existing process through narrowing down to the events and making appropriate changes and improvement on what is done or making changes to the party that does each of the particular activity (Institute for Supply Management 2010). A change for improvement in distribution channel process entails the use of innovative ways to replace or improve the various specific activities performed. Use of these creative options will consequently bring an improvement change concerning quality and process. At the moment, most organizations are applying technology in their operation process to improve the process and reduce the distribution channel costs (Gartner 2013b). With the changing world, technology has always been the best option to be integrated into process improvement. It brings efficiency, and also saves reasonable costs as a distribution channel. Organizations should, therefore, embrace technology in the distribution channel process to save on the costs of distribution (Cudahy 2012). Recommendations As a recommendation, the business organization should venture more into the use of technology to improve their distribution process. With the advent of technology, a business can now make more use of text messaging, emails, push notifications, websites among other technologies to smoothen the distribution channel process. E-commerce also plays a significant role in improving business efficiency and cost reduction in channel distribution. Customers can make orders and payments online from wherever they are. These technology integration possibilities, therefore, shows how technology can significantly reduce the costs. Every business organization can, therefore, look into ways of incorporating technology in operation to lower costs in channel distribution and therefore improve on organization's profit income. Conclusions In conclusion, every organization should manage well its logistic and supply chain to ensure that there are no losses incurred in this process. The organizations should understand its operational challenges associated with the channel distribution used. Cost as a problem in channel distribution should be handled effectively. Organizations should look into ways of cost reduction in channel distribution. The basic approach to cost reduction, in this case, is through choosing the right distribution channel depending on the situational factors. In additional to this, organizations should also work out to reduce costs through breaking down channel distribution units into activities and then handling each activity to ensure that the value derived out of each merges with the cost incurred for the particular activity else it is changed. The right application of these concepts can greatly improve the channel distribution process and therefore bring success to the organization. References Baird, N., Kilcourse, B. (2011). Omni-Channel Fulfillment and the Future of the Retail Supply Chain. Retrieved Match 27, 2017, from https://www.scdigest.com/assets/reps/Omni_Channel_Fulfillment.pdf. Bradley, P. (2013) Collaboration bears fruit. CSCMPs Supply Chain Quarterly, 7(2), 3436. Coelho and Easingwood, 2008 F. Coelho, C. Easingwood An exploratory study into the drivers of channel change European Journal of Marketing, 42 (10) (2008), pp. 10051022 Cooke, J. A. (2013) Kimberly-Clark connects its supply chain to the store shelf. DC Velocity, 11(5): 5355. Coyle, J. J., Langley, C. J., Novack, R. A., Gibson, B. J. (2013) Supply Chain Management: A Logistics Perspective. Mason, OH: South-Western Cengage Learning. Cudahy, G. C., George, M. O., Godfrey, G. R., Rollman, M. J. (2012) Preparing for the unpredictable. Outlook: The Online Journal of High-Performance Business. Retrieved March 27, 2017, from https://www.accenture.com/us-en/outlook/Pages/outlook-journal-2012-preparing-for-unpredictable.aspx. Dittmann, J. P. (2012) Start with the customer! CSCMPs Supply Chain Quarterly. Retrieved March 27, 2017, from https://www.supplychainquarterly.com/topics/Strategy/20121217-start-with-the-customer/. Gartner. (2013a) Gartner Announces Rankings of its 2013 Supply Chain Top 25. Retrieved March 27, 2017, from https://www.gartner.com/newsroom/id/2494115. Gartner. (2013b) IT Glossary. Retrieved March 27, 2017, from https://www.gartner.com/it-glossary/supply-chain-management-scm/. Institute for Supply Management. (2010) Supply Management Defined. Retrieved March 27, 2017, from https://www.ism.ws/tools/content.cfm?ItemNumber=5558. Krause, D. R., Handfield, R. B., and Tyler, B. B. (2007). The relationships between supplier development, commitment, social capital accumulation and performance improvement. Journal of Operations Management, pp 528-545. Lawson, B., Tyler, B.B Cousins, P.D. (2008). Antecedents and consequences of social capital on buyer performance improvement. Journal of Operations Management, Vol. 26(3), pp 446-460 Lawson Nike, Inc. (2013) Global Manufacturing. Retrieved March 27, 2017, from https://manufacturingmap.nikeinc.com/. Partridge, A. R. (2010) Managing a customer-driven supply chain. Inbound Logistics. Retrieved August, 8, 2013, from https://www.inboundlogistics.com/cms/article/managing-a-customer-driven-supply-chain/. Stock, J., Boyer, S. (2009) Developing a consensus definition of supply chain management: A qualitative study. International Journal of Physical Distribution Logistics Management, 39(8), 690711. Sweeney, E. (2011) Towards a unified definition of supply chain management. International Journal of Applied Logistics, 2(3), 3048.