Tourism Trend Research Paper Example | Topics and Well Written Essays - 1000 words - 1

Tourism Trend - Research Paper ExampleHowever, in recent years, Florida has been fitted to develop a novel niche in tourism business called Cruise Tourism. The paper focuses on this new upcoming tourism trend that is making rapid progress in Florida now.In recent years, Florida has wrench a major tourist destination for variety of reasons. Florida theme parks such as Busch Gardens at Tampa Bay, Magic Kingdom, SeaWorld and Typhoon Lagoon at Orlando, Epcot in Disney World offers a unique experience to the tourists. Most of the tourists make a dedicated visit to some(prenominal) of the theme parks in Florida. Sun shines in Tampa Bay, for almost 360 days in a year, lures tourists to come over there. Tampas only water park, Adventure Island mobilize in 30 acres also supplements tourists experiences that they never want to forget (Henthorn, 2014). It is widely known that the US economy suffered immensely due to financial crisis during 2008-2009 accordingly, American spending on leisure travel also declined. In view of the depressed economic scenario, the tourism industry had to extendCruise tourism is sacking to be a future trend in Florida as disposable incomes of the people increases. As per Satchell (2013), Florida is the only state that has some of the busiest cruise ports that include way Everglades, PortMiami, and Port Canaveral. These three ports in Florida generate around 36 percent of the total $19.6 billion business estimated nationwide. It is important to note that in 2012 almost 60% of the cruise tourists began their voyage from Florida registering a 2.6 percent increase over 2011. In 2011, 13.5 million passengers took advantage of cruise ship vacation. Port Miami and Port Everglades have become top cruise ship organizing port in Florida. Port Everglades can boast of having the worlds largest cruise ship a 225,000-ton Royal Caribbean mega ship called the Oasis of

Organizational change in the face of profitability drop in McDonalds Essay

Organizational change in the face of profitability drib in McDonalds Corporation - Essay ExampleIt is evidently clear from the handling that it is undisputable fact that change is inevitable and one of the most fundamental processes of any organization. Presently, than ever before, organizations face rapid change. Globalization and increased expectations of customers and employees, competition, technological advancements, and occupy to boost profitability is what have made change to be inevitable in organizations. Besides, more concern by stakeholders of organizations has prompted the management to adopt change strategies in order to convince the stakeholders that they are capable of achieving the organizational objectives. However, unhomogeneous studies have shown that despite the fact that change is inevitable and most companies management are preparation and implementing change, the process of managing change is proving a great challenge. match to Isern and Pung, leaders rare ly achieve their objectives when they have embarked on a major effort of change in their respective organizations. They note that there are factors that distinguish successful and unsuccessful efforts to change. They argue that a true transformation within an organization is characterized by consolidation of different change types (commercial, operational, and organizational), sustained effort that last for longer periods, and high ambitions. Isern and Pung further note that numerous surveys have shown that have difficulty achieving intended results. According to a 2006 online survey by McKinsey Quarterly only 38 percent of the executives across the globe who responded reported to have had a complete success on the transformations they instituted in their organizations. A tenth of those who responded acknowledged that their organizational transformation efforts were completely unsuccessful (Isern and Pung, 2007, p.1). It is in the light of this that this reciprocation leave behi nd critically evaluate utilize appropriate models, theories and practical interventions how a manager can successfully manage a radical change within a complex organization. The evaluation impart focus on radical change in regard to aspects such as a sharp drop or slide in profitability. The discussion will assess organizational change in the face of profitability drop in McDonalds Corporation. Change Model Managing radical change within an organization may not be an easy task as various surveys have shown. Radical change may be prompted by various circumstances such as enticing new customers, fighting competition, and sharp drop in profitability. Since managing change needs to be done appropriately in order to be successful, it is important that certain model or models be adopted. In this case, and in particular reference to managing change in the face of drop of McDonalds profitability, Kotters 8- Step Change Model will be used. Kotter (1996, p. 26) states the first step in mana ging change is through creation of urgency. Change will be of help to the company if the company really wants it therefore, there is need for development of sense of urgency. Burnes (2009, p.103) agrees with Kotters proposition of creation of urgency around a need by arguing that it is essential in motivating employees in the organization to get things moving. According to Kotter, creation of urgency entails the following examining opportunities that can and should be exploited, identifying potential threats and developing scenarios of possible future happenings, giving of convincing and dynamic reasons so that people can talk and think about them, and requesting support of stakeholders, manufacture players, and customers so as to strengthen the argument about change. McDonald

Business Communication Process for Toyota Essay

Business Communication Process for Toyota - Essay ExampleThe conversation process is fundamental in communicating the corporations refinement to various persons. It would be advantageous for Toyota to employ sophisticated styles of colloquy. In numerous cases, both oral and nonverbal dialogue is instrumental in relaying information (Daneci-Patrau, 2011). Misunderstandings commonly arise when the mode of conference does not fulfill its intended objective during trading operations. Instead, it makes an organization ineffective in conducting its other duties, especially managerial roles. The goal of communication at heart Toyota is to enhance understanding between the sender and the receiver of the information (Guffey, Rogin and Rhodes, 2009). This happens at all levels of operations from the top management to the subordinates. It is often at the departmental level that communication impacts are felt within an organization since it is in such areas that an organizations product ivity can be influenced via communication. Indeed, effective communication assists businesses in achieving their set objectives. In the case of Toyota Corporation, the management can enhance productivity by introducing the application of advanced communication techniques. This will be facilitated by the guidelines on the proposal on the means of improving their communication process using similar approaches to what Digicom uses in within its departments. The information from this piece will be used by other organizations intending to advance the approaches they use in interacting at the operational level. Business Communication Process for Toyota Introduction Modernization is altering the operations of Toyota Corporation. As evident in the corporations outlet across the globe, the communication systems seem to differ while constantly changing to embrace different concerns. For example, the introduction of technology is not only benefiting Toyota but also equally affecting businesse s. Due to these shortcomings, the management has been forced to devise effective measures to enhance communication within their organization (Pride, Hughes, and Kapoor, 2012). In order to effectively comprehend the operations in various departments within the entity, the administrators within the company use modernized approaches of communication as opposed to their traditional methods. Consequently, this paper devises ways which the administrators of Toyota will use in enhancing coordination within operations. The paper equally proffers recommendations that Toyota will use to minimize miscommunication within its organizations, since effective interaction will lead to an increase in productivity the suggestions from this paper should apply to all of the members of the Corporation, regardless of the roles they play. Furthermore, the paper intends to integrate the traditional and the modern approaches to communication that Toyota will use in solving conflicts within the organization. Methodology Data collected from the approaches that Toyota Corporation uses in their communication is instrumental in presenting this proposal.

Japan Westernization Paper Essay Example for Free

Japan Westernization Paper EssayPrompt Discuss feasible reasons why Japan was the only non-western state to nationalize and win recognition as an equal and how it managed to accomplish this in a mere half century. thesis Being aware of recent Western invasions in China, Japan had recognized the need to transform their institutions and its society, therefore, Japan embraced nationalism. By 1649, Japan had shut down rival with the European world with the exception of a Dutch outpost on Deshima Island in Nagaski harbor (this outpost however, was only all in allowed to receive one ship all year). The Japanese also allowed the Chinese to trade at Nagasaki (only under severe restrictions) and Korea could trade through the islands of Tusushima. Other than this however, Japan was isolated.In 1853, the U.S sent Commodore Matthew Perry (with 3 steam clean frigates) to force Japan into opening its ports to trade. Japan had lacked the technology to fight against the U.S and the Europea n powers that soon followed. Slowly (while being under pressure however), Japan opened more than ports granted extraterritorial rights and where able to determine Japans tariff polices. Like China, Japan seemed to be getting controlled by the European powers. However, young, vigorous leadership took control of the government of Japan forcing a dramatic reconstruction of the nations polices, administration, class structure, economy, technology and culture. These leaders tended to be young samurai warriors in the han (feudal estates) of Choshu and Satsuma.The samurai were able to employ roughly of the technological information introduced by the Dutch from their station in Nagasaki harbor (the shogunate had established an office for translating Dutch material in 1811) and by 1840, some(prenominal) of the Japanese were already casting Western guns and artillery. A new leader, Sakuma Zozan (one of the advocates of adopting Western military methods) believed that opening the country w as necessary and beneficial. However, not everyone had agreed. In 1860 a separate of samurai (from the conservative han of Mito) argued a different opinion and eventually, Mito loyalists assassinated Sakuma. In 1868, forces of Choshu and Satusma (along with several more remote hans) took control of the emperors palace in Kyoto and say the end of shogunate. The emperor was put back into imperial power.

Free

fire Will vs Determinism EssayThe debate, reposition result versus determinism, has been long debated for centuries. Free will is a concept that holds individuals responsible for the transaction and decisions of their lives. Adversely, other individuals believe ones life is predetermined. For the purpose of this essay I will prepargon dialogue between myself and philosopher Socrates. I will withal define free will and determinism. The Dialogue XXXXXX Determinism is interpreted as the philosophical theory or doctrine in which an individual believes that action from humans are unavoidable occurrences in nature are more than likely caused by preceding issuings or natural laws. XXXXXX Free Will is the qualification of humans to pack freedom freedom to make choices freely without the influence of others or nature better said, as the ability to act freely within limits. XXXXXX No. I do not agree that all event has an explanatory cause. I would like to think its fair to say not every event or situation warrants an explanation. Lets say, for example, God developed in mind or physically, tenner Eve, also accommodated them a garden with every fruit, with the censure of forbidden fruits. In consequence, they disobeyed.A fair argument would be that there is no way to argue an explanatory cause in connection with Adams Eves selection free will came into existence. XXXX Id say birth, wedding and funerals would be examples of events XXXX Explanatory cause would suggest keister every event that occurs has an explanation to persuade an explanation for why events happen. XXXXX As referenced previously, I dont agree with explanatory causes for events that happen in human life. Only selected events have an explanatory cause such as death, for example.Death was already predetermined at which time man was created. XXXXX Choices of humans is the ability to make sound decisions without influence, freedom of choice. In this day and age humans are held to the highest d egree of responsibility for their own actions. Judicial systems have been put into bum for this very reason. Events occur from human action or choices. Absolutely, Choice and events are completely different. XXXX Absolutely not Socrates, It is not a known fact that every action has an explanatory cause is completed dependently.Some actions may be simply due to determinism however, at the same instance may be in connection with ones free will. Murder would be great example. This would be a solely act carried out by an individual free will. XXXXx Exempt from external authority, an individuals will, unrestricted. Free. XXXX Absolutely, why not despite individuals having the freedom of choice, within limits due to higher existing authority. Its reasonable to bring to the conclusion that free will is not completely free, external influences do exist.The two can coexist. XXXX Possibly determinism but not internal free will. Free will cannot be classified as internal or external factors. In Conclusion, determinism vs. free will is a debate that has been debated over centuries. This debate will continue to obtain conflicting attention for many years to come from a variety of people. In this paper I have discussed briefly the comment of free will and determinism. I have also presented dialogue between the deceased Socrates and myself in attempt to shed more on this highly disputable topic.

Study Of Variable Valve Timing Engineering Essay

Study Of Variable Valve Timing locomotiveering EssayVariable Valve Timing is a tool in which the lift, du dimensionn or timing of either the wasting disease or run over valves or both croup be altered in some(prenominal) combinations during engine operation. This is not possible for an engine with fixed intake and exhaust valves. An engine with VVT installed helps in improving engine performance over a wider outrank of the engine operating spectrum. In this paper, the effect of VVTs on gasoline as well as diesel engines were discussed and also comp atomic number 18d to their series counter transgresss. For a diesel engine, it was ascertained that with the introduction of a VVT, higher(prenominal) go off-line and blaze pressures were achieved with inadvertently led to a better engine performance along with let down smoke density and higher torque at low securenesss. Minute variations in CO, NOx and PM emissions were observed. However at integral- commitment operation, NO x emissions had change magnitude marginally. In the slip-up of the gasoline engine, it was observed that there wasnt any significant improvement in the CO and NOx emissions. However, the engine torque had increased particularly at low recreates and at incomplete load. This was complimented by a decrease in Brake Specific Fuel Consumption (bsfc).INTRODUCTIONThe valves in 4-Stroke IC Engines argon mostly spring operated 1. The coal scuttle and closing of these valves is governed by the crankshaft which is machine-accessible to the valves through an intermediary camshaft which is attached to every valve through a cam. The amount of fuel that enters the combustion chamber is dependent upon valve timing. The camshaft is connected to the crankshaft by using any one of gears, chains or belts. In conventional engines without VVT, the cam lobe shape and position as well as it profile are tuned for a particular engine speed and this usually compromises high-end torque or low-end power. However, with the introduction of VVT, the cam characteristics, e.g. timing, can be altered. Thus, this allows for better engine efficiency and power at variable engine speeds 2.This is workful especially at high speed operation where a car requires to a greater extent air in order to verbalize the undeniable power. If lesser amount of air were to be entered at high speeds, there would a considerable decrease in performance. However, if the valves were to be kept candid for a longer duration, there would be a case of incomplete combustion inside the combustion chamber at low speeds since the pressure involve to attain proper combustion of fuel is insufficient. This again results in reduced engine performance as well as an increase in fuel emissions 2.Modern emission regulations set by various governments have forced several manufacturers to adopt VVT in their engines. Most of the current car manufacturers have espouse VVT engine systems.The popular VVT mechanisms are classifie d into purely mechanical, electro-mechanical and hydraulic. Purely mechanical VVT systems are further classified into Oscillating Cam, Eccentric Cam Drive, Three-Dimensional Cam Lobe and Two sleep together Combined Profile 2.TYPES OF VVTsPurely MechanicalIn this type of VVT, the valve timing is operated by mechanical means. It is further subdivided intoOscillating CamThis method involves using either a conventional cam lobe or an eccentric and connecting rod which generates oscillatory motion on part cam lobe which is connected to the follower and thus, the valve. The part lobe is made up of a dent each of base circle and lobe flank. The position of the part cam lobe can be varied depending on whether zero lift and zero position are required in which case the part cam lobe is completely base circle. The exact opposite situation is maximum duration at full lift in which case it is fully flank. BMWs Valvetronic, Toyota Valvematic( both conventional) and Nissan VVEL( eccentric and co nnecting rod) are variations of this method. The Valvetronic is very dependable however the lift duration is dependent on amount of lift. Hence its only use on intake valves. The Valvematic and the VVEL are more compact while delivering the same performance as the Valvetronic 2.Eccentric Cam DriveThe Rover Company is the only smart set in history to have ever used this version of VVT. In this method, an eccentric disc mechanism is used which can vary the angular speed of the cam. The lesser the angular speed, the greater the duration of lift. The disadvantage of this method is that its expensive as each valve requires its own controller 2.Three-Dimensional Cam LobeThis system comprises of an axially lengthen cam lobe which has shorter duration profile and a greater duration profile at either ends. Thus, valve lift duration can be varied by tilting the cam lobe axially. However, such(prenominal) a system requires the follower to tilt in various directions as the lobe flanks of the cam lobe are not parallel to the axis of rotation of the camshaft. This problem has never been rectify which is why its not used commercially 2.Two Shaft Combined ProfileIn this system, two closely arranged camshafts are used. The angular positions of the camshaft with think of to the crankshaft can be arranged by using a phasing mechanism. A follower connects both camshafts and is operated by the two lobes simultaneously. The two lobes are used for the intake and exhaust valves respectively. The disadvantage of this system is that the settings on one lobe may affect the other thus tampering the entire system. It has yet to be used commercially 2.Electro-mechanicalCamless engines use this type of VVT in which the valve opening and closing is achieved by using electro-magnets. The disadvantages of this systems are deceleration of the valve is hard to achieve, springs used in the valves have to adjusted to the smallest of margins and finally, the use of electromagnets reduces the en gine efficiency 2.HydraulicAnother system developed as an alternative to cam engines. In this system, the pressure of the liquid is used to activate valves. However, this system has its disadvantages. The verve required to operate a highly active hydraulic system under different circumstances is very high. The viscosity of the hydraulic fluid can vary over different temperatures. The use of springs deters high engine speed generation. The adequate operation of this system requires the aid of powerful computers and accurate sensors 2.GASOLINE ENGINES WITH VVT INSTALLEDVVT was installed in a gasoline engine and it was observed that for optimal performance, the inlet valve the inlet valve closing(IC) and the exhaust valve(EC) opening periods have to be optimised. The maximum temperature and pressure obtained in the combustion chamber is a result of IC optimisation. Optimal timing for each valve is dependent on engine speed. This characteristic is shown for both IC and EO at part load as well as full load through figures 1 and 2.CUsersUSERDesktopoptimal EO vs engine speed.png habitus 1 Optimal EO Vs Engine pep pill3CUsersUSERDesktopOptimal IC vs engine speed.pngFigure 2 Optimal IC Vs Engine Speed3Figures 3,4,5 and 6 compare tortuousness produced, bsfc, CO emissions and NOx emissions respectively for a blueprint engine and an engine with VVT installed at full load.CUsersUSERDesktopTorque vs engine speed, full load petrol.pngFigure 3 Torque Vs Engine Speed at full loadCUsersUSERDesktopbsfc vs engine speed,full load petrol.pngFigure 4 bsfc vs Engine Speed at full load3CUsersUSERDesktopCO emissions vs engine speed, full load petrol.pngFigure 5 CO emissions Vs Engine Speed at full load 3CUsersUSERDesktopCO emissions vs engine speed, full load petrol.pngFigure 6 NOx emissions Vs Engine Speed at full load 3Its observed that VVT has little or no effect on the CO or NOx emissions. However, the torque produced has increased by 6% accompanied by a bsfc decrease of 2% 3.Similarly at part load, the torque produced, bsfc, CO and NOx emissions were compared for both engines and the results are indicated in figures 7,8,9 and 10 respectively.CUsersUSERDesktopTorque vs engine speed, part load petrol.pngFigure 7 Torque produced vs Engine Speed at part load3CUsersUSERDesktopbsfc vs engine speed, part load petrol.pngFigure 8 bsfc vs Engine Speed at part load 3CUsersUSERDesktopCO emissions vs engine speed, part load petrol.pngFigure 9 CO emissions Vs Engine Speed at part load 3CUsersUSERDesktopNOx emissions vs engine speed, part load petrol.pngFigure 10 Nox emissions Vs Engine Speed at part load 3At partial load, its observed that the torque increases by 4% and 3% when the engine is rotating at 2000rpm and 5000rpm respectively complemented by a bsfc decrease of 6% and 14%.The main advantage of the VVT for a gasoline engine is maximum torque can be achieved at a lower speed of rotation 3.DIESEL ENGINES WITH VVT INSTALLEDThere are a number of factors which have hampered the research of VVT in diesel engines. Two of those factors are the complexity of VVT engineering and the rapid evolution of diesel engine technology. Due to the lean nature of air fuel mixture, diesel engines emit much less CO as compared to their gasoline counterparts. This is because of the absence of unburnt hydrocarbons in the mixture. However, due to higher temperatures involved in diesel engines owing to higher compression ratios, NOx are much more prominent as compared to gasoline engines 4.Since diesel engines operate under higher compression ratios, the gap between the valves and the top of the piston at Top groundless Centre (TDC) is very minimal. Therefore, the VVT has to be designed such that there is no contact between the valves and the piston.Figure 11 shows the variation of torque with engine speed by only varying the inlet valve closingCUsersUSERDesktoptorque vs speed, IC diesel.pngFigure 11 Torque Vs Engine Speed at full load with in let valve closing control 4It is observed particularly at low engine speeds that the maximum torque increases at low speeds. In this case, there was a 6% increase in torque at 1000rpm and 8% increase at 1600rpm.A similar pattern is observed by controlling the exhaust valve opening (EO) as well as the combined control of EO and IC. This is indicated in figures 12 13 repectively.CUsersUSERDesktopTorque vs engine speed EO diesel.pngFigure 12 Torque Vs Engine Speed at full load with EO control 4CUsersUSERDesktopTorque vs engine speed EO,IC- diesel.pngFigure 13 Torque Vs Engine Speed at full load by controlling EO ICAt part load is was observed that by closing the inlet valve before Bottom lifeless Centre (BDC), the bsfc had reduced 4.Figure 14 shows the effect of IC timing on effective compression ratio after the installation of VVT.CUsersUSERDesktopCompression ratio IC- diesel.pngFigure 14 Effect Of IC Timing On Effective Compression Ratio 4It is clear from figure 14 that by adv ancing the IC after BDC the compression ratio increases inside the combustion chamber.CONCLUSIONThe need for Variable Valve Timing has been discussed in detail. The various types of VVTs popularly have been discussed briefly. Most of mod vehicles use VVTs mainly due to legislation. The effect of using VVT in a gasoline as well as a diesel engine was analysed and explained accordingly. It was sight that though there wasnt any appreciable decrease in emissions, the maximum torque produced was attained at a lower speed compared to their series counterparts. Also, the bsfc in both cases had been reduced.

Porous Silicon p-type with Different Current Density

permeable ti p-type with Different Current DensityPhotoluminescence and Band Energy Gap For Porous Silicon p-type with Different Current Densityand Different Etching Time1Mohammed Jabbar Hussein, *1W. Mahmood Mat Yunus, 2Halimah Mohamed Kamari3Josephine Liew Ying Chyl,AbstractPhotoluminescence (PL) for holey silicon lead to studied by many interrogationer .this phenomenon which has application in many devices. Porous silicon can be used in the optoelectronic devices and sensor. Therefore, the study to development holey silicon is very necessary,. In this study, porous silicon was active by chemical etch used silicon , the based electrolyte was ued HF acid with ethanol 11 . The porous silicon was characterized by Photoluminescence Spectrometer (PLS) and (SEM) Microscope. The range of the porosity (20.33 78.2) % and it is dependent on true denseness and print time. The has Band quip cypher which is from 1.81 ev to 2.o7 ev , the mob cattle farm energy is increased wit h change magnitude certain tautness and increasing etch timeIntroductionSince the discovery of visible luminescence in the room temperature 15, porous silicon (PS) has become a subject of considerable interest, optoelectronic device 6,7. many several methods 810 for fabricating PS from crystalline silicon wafers. The electrochemical etching 1,8. Both method is the difference between them the chemical etching without utilise the external bias, therefore, considered this method the localized electrochemical process chemically 11. Porous silicon was discovered in 1956 by Uhlir ( Uhlir 1956) while performing electro polishing experiments ,hydrofluoric acid (HF) was prepared in to silicon wafer by electrolyte containing . He found that beneath the fascinate conditions applied ongoing and solution composition , the silicon did not dissolve uniformly but instead fine holes were produced, porous silicon formation was obtained using electrochemical dissolution of silicon wafer in a queous or ethanoic HF solution The surface dependency of the PL energy , which explains the efficient luminescence , causes the peaks to sift towards the high energy or lower wavelength , as already reported 12,13 ,the red shift in PL peaks with decreasing average size of Si structure size in psi is considered to be strong evidence that the visible PL is caused by the quantum confinement effect 14 . The degree of the blue shift for psi usually depends forwardness condition , Si resistivity , substrate ,type and dopant concentration , which can cause different modification of psi microstructure during anodisation 15 The values of the band gap energy of the porous silicon are the same range of the reported ( 1.5ev to 2.5 ev) 16.17,18 In this work , porous silicon p-type was prepared by electrochemical etching technique and photoluminescence PL spectrometry was used to determine the wavelength the emitted light .Preparation porous siliconAll experiments were prepared on (100) n- type silicon (Si) single crystal wafers of 537 thickness. Silicon substrates were cleaned by sonification for 5min in ethanol, and acetone. A Si substrate was placed at the bottom of a cylindrical Teflon cell and fixed by an aluminium eggshell as a backing material. A platinum (Pt) rod serves as a cathode perpendicular to the Si surface at a distance of (1cm). The samples were prepared with constant current, density, and etching time at a concentration of ethanol ( in the volume ratio of 11. Theaside is an essential ingredient for the anodical etching of . fermentation alcohol was added into electrolyte to enhance the homogeneity and uniformity of the () surface because it acts as a promoting agent to increase the wettability of () surface and to remove the extraneous H2 bubbles that appear during the anodical etching process. In fact, ethanic solutions pass through the pores, while purely aqueous HF solution does not. This is very important for the lateral homogeneity and the u niformity in depth of the () layer. A digital current source () was used to supply constant current. Figure (1) visual aspects the schematic diagram of all the elements used for the preparation of (). To generate the electron hole pairs, the surface of sample was illuminated with halogen lamp () during iodisation. For all samples, a voltage of was applied to the halogen lamp for illumination. The current densities used for samples are 10 mA/cm2, 20 mA/cm2, and 30 mA/cm2 with etching times of 20mins, 40mins, 60mins, and 80mins. HF based electrolyte Pt electrode Teflon cell Si wafer Current source AL plateFigure 1 Schematic of electrochemical etching cell for iodisation of () samplesFigure (2)porous silicon (). a without light .b)with light .c) after remove the porous . Figure(3) SEM images of PSi a) silicon wafer as carapace 1m, b)-porous silicon (). as scale. c) porous silicon as scale 500 nm .d) porous silicon as scale .Results and discussionThe optical properties of psi s amples electrochemically etched at three different current density and by varying etching time. Figures (4- a,b,and c) shows the variant of PL spectra with etching time for the psi samples obtained at the current density 10 mA /cm2 , 20 mA/cm 2, and 30 mA/cm2. The intense luminescence spectra emitted from porous silicon structures formed on the samples. The pl peaks show a steady red color shift from 500 nm to 800 nm with increasing the etching time .,Figures (4-a,b,c) PL peaks for porous silicon samples prepared under differnet etching time with the current density a) 10 ma/cm2 ,b)20 mA/cm2 ,c)30 mA/cm2. respectivelyThe Figure (5) show the PL spectra of samples prepared by current density of 10, 20 and 30 , respectively ..The band gap energy () was inferred from (PL) wavelength () using (. the relationship between band energy gap with the current density and etching time is increased the band energy gap when the current density and etching time increasing 19 . Figure (5-a,b) show the energy gap () variation of psi samples as a share of etching time and current density , respectivelyFigures (5-a,b) Band energy gap as a function to a) etching time with different current density ,b) currents density with the different etching time . RespectivelyFigure (6) show the band energy gap versus the porosity for three different current density of the samples and deferent etching time. The band gap energy value is not linearly increased with increasing porosity because the change in the structure size of the silicon. The results show the dependency of the band gab energy value to the current density especially in high porosity 16Figure (6) .band gap energy as a function to porosity with different current density.Table (1) .the values of porosity, band gap energy, and PL peaks intensity for porous silicon with different current density and different etching timeTable (1) shows that the band gap energy increases from ( 1.82 ,1.90,194,and 1.97 ) ev to (1.86,1.91,196,and 2,01) in etching time (20,40,60,and 80 )min respectively when the current density increasing from 10 to 20 ,also the increases the band energy gap from ( 1.86,1.93,196,and 2,01) ev to ( 1.93,1.97,2.01 ,and 2.07 ) in the etching time20,40,60,and 80 )min respectively when the current density increasing from 20 to 30. The results show an increase the band energy gap when the etching time increasing. That mean the band energy gap depended of the current density and etching time . the results shown the band gap energy is increased with etching time , it is increase from (1.82,1.86,and 1.93 ) ev to (1.90 , 1.93 , and 1.97 ) ev in the current density (10,20,and 30) mA/cm2 respectively when the etching time increasing from 20 min to 40 min . as well to some other etching time from 40 min to 60 min and from 60 min to 80min .Conclusion.In summary. The results show for the effects the etching time and current density to the band energy gap and the porosity. In this experimental the band ener gy gap is increased with increasing the current density the band gap energy increases from ( 1.81 ,1.88,194,and 1.99 ) ev to (1.86,1.91,196,and 2,01) in etching time (20,40,60,and 80 )min respectively when the current density increasing from 10 to 20 , . as well to another current density ,also the band energy gab is increased from (1.81,1.86,and 1.93 )ev to (1.88 , 1.91 , and 1.97 ) ev in the current density (10,20,and 30) mA/cm2 respectively when the etching time increasing from 20 min to 40 min . as well to another etching time .AcknowledgmentThe authors would like to thank Physics Department in the University Putra Malaysia for providing the research fealties.References1Canham, L.. (1990). Silicon quantum wire Applied Physics Letters,57(10), 1046-1048.2Lehmann, V., Gsele, U. (1991). Porous silicon formation A quantum wire effect.Applied Physics Letters,58(8), 856-858.3 Searson, P. C., Macaulay, J. M., Ross, F. M. (1992). 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