Saturday, December 7, 2019

Ladder and Functional Block Diagramming

Question: Describe about the Ladder and Functional Block Diagramming? Answer: Programmable Logic Controller is a the part of industrial environment, which is used for facilitating automation in factory assembly lines. It is basically a digital computer which is used to control the machines of factory assembly lines and lighting fixtures. PLC programs should be documented to track the process of PLC. If there are any error in the program then it is used to track back to know the area where the problem occurs. The documentation of PLC is important, and the steps to be followed to document PLC are: The documentation would be in the form of flow chart to understand the process graphically, with a proper explanation the program step-by-step. All the inputs and outputs are to be listed out which helps the programmer to understand how the functions are working. All the step-by-step programs are to be documented so that the function of tracking back operations becomes easier. PLCs have positively impacted process control and automated systems.Automation is a technology which is concerned about performing various process with the help of programmed commands, the commands being used to execute the proper instructions. However the process of automating a systems results in a more complex as well as sophisticated system. It represents both levels of capability as well as performance to surpass the ability of human beings to achieve the same activity. Using PLCs, the process control system provides both accuracy and stability in the production process. Many operational tasks which are complex are to be solved by using PLC. In an automated system, PLC becomes the central part of the process control system. At the time of running more complex processes, more PLCs are to be connected with the central computer. Now-days, PLCs are to be used to control and automate the job in single machine to increase the automation of manufacturing or testing process. The limits or disadvantages of using PLCs in process control and automated systems are the lack of standardization. This causes much confusion if the PLC used for an application is replaced by one from a different manufacturer or if a PLC programmer is replaced by a person with a different understanding of PLC programming Advantages of Flow chart in PLC: It is simple to understand and also describes a process graphically, so that the process which is being used is understood by everyone on the plant. Flow chart will explain the program step-by-step. The time required to design a control system should be decreased by using flowchart programming. Disadvantages of Flow chart in PLC: As the symbols of flow chart cannot be typed so creation of flow chart will be a problem. At the time when the program logic is complicated then the flow chart also becomes complex. Advantages of Truth table in PLC: The truth table in PLC describes what actually the circuit should do. In the truth table, the activities of the circuits are described properly, such that one can understand the exact logic following which the circuits operates. Using truth table, theapplications of the logic gates used to design the circuit can easily be understood. Disadvantages of Truth table in PLC: It is difficult to understand the logic gate when the circuit is complex. Advantage of Logic function diagram to design in PLC: Logic function diagram has developed a programming language which is used to represent a program by a graphical diagram based on thecircuit diagrams of relay logic hardware. Disadvantage of Logic function diagram to design in PLC: One of the disadvantages of designing the circuit is the lack of portability Offline programming: It allows modification as well as development of programs without being connected to PLC processor. Online programming: The ability to modify, monitor and create data as well as program sequences at the time when PLC processor is both online and/ or in run mode. Advantages of Online Programming: It allows changes without stopping the immediate feedback as well as process. Disadvantages of Online Programming: the entire circuit experiences various risk situations in case of any failure: damages may occur in the equipment , besides giving rise to safety problems. Advantages of Offline Programming: It is safer as the machine gets stopped in case of a failure and affected personnel will be able to detect the issues when a new code is to be tested. Disadvantage of Offline Programming: It causes error as offline program contains untested code. The methods be used to debug the PLC program are the following: Static Analysis: It analyzes the software to gain some information about it. It gains accesses to the actual instructions that the software has been executing. The limitation of static analysis is that it requires access to the source code and it is unable to find the issues which are related to operational deployment environment. Dynamic Analysis: It is used to test the software: in order to identify whether it functions properly under various hypothetical situation. The advantage of such system is that it needs to test a system in an operating condition to perform the test: it does not require any source code. The limitation of such an analysis is that it is not able to test the actual instructions which are being executed. Correction-based Debugging: It is used to obtain the accuracy while considering the desired output responses at the observation point. It is a cost effective method. The limitation is that it consumes a lot of time to debug the PLC programs (Sulflow and Drechsler, 2015). A programming panel is used at the time when a program is to be transferred from PC to PLC After transferring the program, an option is to be given to compare this program. PC is evolved to include the functionality of PLC. PC is a robust controller which allows operating in harsh environment. The comparison between the programs is to be done based on some major areas such as operation, serviceability, security, safety, robustness and hardware integration. PC can accomplish the same reliability as PLC. Safety is major concern for the entire user.The comparison is important to identify which is best PC or PLC. References: Bolton, W. (2015). Ladder and Functional Block Diagramming. [online] Available at: [Accessed 27 Jun. 2015]. Lipson, P. and Zalm, G. (2015). [online] Available at: [Accessed 27 Jun. 2015]. Programmable Logic Controller. (2015). 1st ed. [ebook] Available at: [Accessed 27 Jun. 2015]. Rockwell, (2015). Programmable Logic Controller. [online] Available at: https://file:///C:/Users/AVERI/Downloads/pet10882OLCSampleChapterconstrained72.pdf [Accessed 27 Jun. 2015]. Sulflow, A. and Drechsler, R. (2015). Automatic Fault Localization for Programmable Logic Controllers?. 1st ed. [ebook] Available at: [Accessed 27 Jun. 2015].

Friday, November 29, 2019

Story of My Life Summary Essay Example

Story of My Life Summary Essay This ticket will only be valid along with an ID proof in original. If found travelling without ID Proof,Passenger will be treated as without ticket and charged as per extant Railway rules. Valid IDs to be presented during train journey by one of the passenger booked on an e-ticket :- Voter Identity Card / Passport / PA N Card / Driving License / Photo ID card issued by Central/State Govt. /Public Sector Undertakings of State/Central Government, District A dministrations, Municipal bodies and Panchayat A dministrations.Student Identity Card with photograph issued by recognized School or College for their students / Nationalized Bank Passbook with photograph /Credit Cards issued by Banks with laminated photograph / Unique Identification Card A adhaar. General rules/ Information for e-ticket passenger have to be studied by the customer for cancellation refund. PNR No: 2821756814 Transaction ID: 0738114571 From : FAIZABAD JN(FD) Boarding: FAIZABAD JN(FD) R e sv Upto: DELHI(DLI) Passe ng e r Mobile Num be r: 9953892375 Train No. Nam e : 14205/FD DLI EXP Date of Book ing: 16-Aug-2013 07:02:07 PM Date of Journe y: 26-Aug-2013 Date of Boarding: 26-Aug-2013 Sche dule d Arrival: 27-Aug-2013 09:35 * Q uota: Ge ne ral C lass: SL To: DELHI(DLI) Sche dule d De parture : 21:45 * Adult: 01 C hild: 00 Distance : 0615 KM Passenger A ddress :- E 6/162 GALI NO 6A BLO C K E SANGAM VIHAR ,NEW DELHI Ne w De lhi De lhi 110062 FA RE DETA ILS : S. No. De scription 1 2 3 Tick e t Fare IR C TC Se rvice C harge s# (I nc l. of Servic e T ax) Am ount (In rupe e s) Am ount (In words) R s. 290. 0 R s. 11. 24 R s. 301. 4 R upe e s Two Hundre d and Nine ty and Ze ro Ze ro Paisa O nly R upe e s Ele ve n and Two Four Paisa O nly R upe e s Thre e Hundre d and O ne and Two Four Paisa O nly Total am ount be fore C ance llation # Se rvice s C harge s pe r e tick e t irre spe ctive of num be r of passe nge rs on the tick e t. PA SSENGER DETA ILS : SNo. 1 Nam e Manoj Age 35 Se x Male C once ssion C od e Book ing Status/ C urre nt Status/C oach No. /Se at No C ance lle d 0000/ This ticket is booked on a personal user ID and cannot be sold by an agent. If bought from an agent by any individual, it is at his/her own risk.IMPORTA NT: For details, rules and terms conditions of E-Ticketing services, please visit www. irctc. co. in. *New Time Table will be effective from 01-07-2013. Departure time and A rrival Time printed on this ERS/VRM is liable to change. Please Check correct departure, arrival from Railway Station Enquiry, Dial 139 or SMS RA IL to 139. There is amendments in certain provisions of Refund Rule. Refer A mended Refund Rules w. e. f 01-07-2013. The accommodation booked is not transferable and is valid only if one of the ID card noted above is presented during the journey.The ERS/VRM/SMS sent by IRCTC along with the valid ID proof in original would be verified by TTE with the name and PNR on the chart. If the passenger fail to produce/display ERS/VRM/SMS sent by IRCTC d ue to any eventuality (loss, damaged mobile/laptop etc. ) but has the prescribed original proof of identity, a penalty of Rs. 50/- per ticket as applicable to such cases will be levied. The ticket checking staff On board/Off board will give Excess Fare Ticket for the same. E-ticket cancellations are permitted through www. irctc. o. in by the user. Obtain certificate from the TTE /Conductor in case of PA RTIA LLY waitlisted e-ticket, LESS NO. OF PA SSENGERS travelled, A . C. FA ILURE, TRA VEL IN LOWER CLA SS. This original certificate must be sent to GGM (IT), IRCTC Ltd. , Internet Ticketing Centre, IRCA Building, State Entry Road, New Delhi-110055 after filing on-line refund request for claiming refund. Passengers are advised not to carry inflammable/dangerous/explosive articles as part of their luggage and also to desist from smoking in the trains.Contact us on: 24*7 Hrs Customer Support at 011-39340000 , Chennai Customer Care 044 – 25300000 or Mail To: [emailprotected] co. in. For any suggestions/complaints related to Catering services, contact Toll Free No. 1800-111-321 (07. 00 hrs to 22. 00 hrs) https://www. irctc. co. in/cgi-bin/bv60. dll/irctc/services/printTicket. jsp? [emailprotected]@@@1646364332. [emailprotected]@@@BV_EngineID=cccgadfkkgjkml†¦ 1/2 8/25/13 IRCTC Ltd,Booked Ticket Printing https://www. irctc. co. in/cgi-bin/bv60. dll/irctc/services/printTicket. jsp? [emailprotected]@@@1646364332. [emailprotected]@@@BV_EngineID=cccgadfkkgjkml†¦ 2/2

Monday, November 25, 2019

Book Report on Fast Food Nation

Book Report on Fast Food Nation Free Online Research Papers When reading a novel there are many expectations that come to mind before even opening it up. Is the book going to capture my interests? When reading this book am I going to understand the concept that is it trying to tell the reader? That is what I said to myself when before reading the novel â€Å"Fast Food Nation,† by Eric Schlosser. This book breaks down the dark side of the all- American meal. It goes through each topic one by one that many people may wonder about the fast food that they are eating. When I found out that I was going to have to read this book for my class I thought that it would just the book version of the movie, â€Å" Super-Size Me.† But then after reading the first chapter I realized it was something completely different. While reading this book there was some information that was disturbing to read. When finding out what they do to the cows and how they slaughter them was sad to hear. The chapters of the book cover many different topics. These topics range from the founders of the first fast food stand, how they make the fries, working in the slaughterhouse and the dangers that it causes to its workers, and global realization (how fast food has changed the world). Every time I read this book I learned more information that I never knew about the fast food industry. If I were to give this book a rating I would give it a ten. This book may not be welcoming to readers but it is very insightful. Who knew that the fast food industry is the largest place for teenagers to get jobs? I found out in this book that most teenagers once in their lives have worked in the fast food industries. Also I found out that the McDonalds brothers were the ones who began the first Speedee Service System. When reading this novel the author provides a historical backdrop of the fast-food nation. Each chapter of this book has to deal with different people. I was most interested in learning about Ray A. Kroc. I found that interesting because I live in San Diego and he used to be one of the physical education teachers at my middle school and the Kroc Center is just minutes from house and I have spent some time there in their activates department participating in pool and their indoor ice skating rink. The author also talks about Walt Disney, and his complicate relationship with Mr. Kroc and his rise to fame. Learning about these important characters was very interesting to me. Of course both these men became very successful businessmen but I enjoyed hearing about their struggles before entering the light of fame. Reading this book did not really affect my way of eating fast food. Actually while reading this book I began to get hungry for some sort of big mac and fries. I found this book more interesting then disgusting. I was upset reading one part of the book though. Hearing about the workers at the slaughterhouse made me sad. This chapter of the book is to consider how workers in the meatpacking industry are damaged because of the way the plants are managed. The author talks about the specific hazards that is included when working here. Such as the dangerous machinery, the impractical expectations for production, the poor working conditions, and the fact that the supervisors do not bother to help the injured workers, instead they just move them to an easier job until they are better to go back to their original job. â€Å"Schlosser also places blame on the Reagan administration for undoing the advances that had been made for worker since the beginning of the twentieth century,† (Fast Food Nation). Interviews are done in this book; the author talks to some of the late night clean up crew and tell the readers the horrors of working the midnight shifts. The late night cleaning crew consists of mostly illegal immigrants. These immigrants suffer the most pain when working but reporting their injuries could result in being deported back to their country. One worker stated that he has lost two fingers and went into shock, the next week he returned to work and said that if one hand was not working he had another one to use. (Fast Food Nation). The smells that come with working in the slaughterhouse are awful, many workers say they come home smelling so powerful it takes days to go away no matter how many showers they take. As you can see being in the fast food industry is stressful, whether you are working behind the counter or in the slaughterhouse. I would recommend this book to anyone. I think all high school students should read this book and get educated on the pros and cons of working for their local fast food industry. Reading this book did impact my life . I know that getting a good education can result in a good paying job and a job that will not send me to the hospital or have a hot oil burn from French fries being cooked. I would not take out any information form this book because it is full of so much information that anyone reading would want to know. Learning about the products that are in the meat and the fries may interest many people so they know what kind of things they are putting into their bodies. I enjoyed reading this book and I would do it again if it was necessary. Research Papers on Book Report on Fast Food NationBook Review on The Autobiography of Malcolm XTrailblazing by Eric AndersonHarry Potter and the Deathly Hallows EssayStandardized TestingEffects of Television Violence on Children19 Century Society: A Deeply Divided EraThe Hockey GameNever Been Kicked Out of a Place This NiceMind TravelQuebec and Canada

Friday, November 22, 2019

The Career of a Manager Essay Example | Topics and Well Written Essays - 1000 words - 8

The Career of a Manager - Essay Example At present, I possess certain skills that would be helpful in pursuing my career as a manager. For example, I am quite proficient in the field of accounting and statistics. These skills are vital for becoming a manager as accounting would help me in managing the financial resources in a better way and statistics would aid in forecasting demands efficiently. However, as a manager, my prime concern would be generating profits for an organization. Creation of sufficient profits is concerned with the better management of risk and proper investment (Saville Consulting, 2008; Pollak, 2011). However, I do possess certain limitations that can hinder my career progression. In this similar context, it is to be mentioned that managing a big organization would be a quite challenging task for me. The significant amount of time and effort must be devoted to the proper management of a business linked with such organizations (Amtek Engineering Ltd, 2010). Thus, according to my viewpoint, I need a st rong and capable team, which can assist me to undertake various duties and fulfill the organizational objectives. I will require developing team management skill and other vital managerial skills in order to become a manager. At present, I did not decide to which field of management I would prefer to pursue my career. Among various fields, I am planning to become a marketing or financial manager. This career has attractive potentialities and opportunities in the modern era. Thus, an effective plan has been made in the following based on which I could successfully pursue my career and at the end become a potent marketing or financial manager. In order to pursue my career, I would like to understand regarding the world of business and administration. Thus, I will enroll in Foundation degree in business from Warwickshire College. Furthermore, I will learn about the nature of business organizations and the environment wherein they operate.

Wednesday, November 20, 2019

Apple Company Essay Example | Topics and Well Written Essays - 1000 words

Apple Company - Essay Example It took Apple only five years from 2003 to 2008 to have the market value of its shares increased by as many as 25 times, as the value of Apple’s share in 2003 was $7.5 which increased to $180 in the year 2008. â€Å"At July 2008 prices, before the US Financial Crisis, Apple stock market capitalization was $160 billion. In January 2010 Apple shares topped the $210 mark† (Vertygo Team, 2011). The case study of Apple Company provides an excellent practical example of how the theoretical marketing principles can be brought to life by incorporating them into the business strategies, and their benefits can thus be obtained. This paper discusses the potential ways of integration of the marketing theory with practice, and explores the comprehensive marketing strategy adopted by the Apple Company that has led it to the profound success. The secret of Apple’s success lies beyond the design standards of its products as well as the core philosophy of Apple which suggests tha t â€Å"the user doesn’t always know what they want† (Tiojanco, 2012). ... potential hurdles in the way of integrating marketing theory with practice, and recognition of the measures that can be taken to overcome those obstacles. Subjectivity in the knowledge of marketing theory is introduced by the conflicting and complimenting marketing theories of different scholars and educationalists. There is not a single established way of marketing that has gained mutual consensus of all scholars and authors. In fact, different good practices have been explained in different books and literatures depending upon the context, circumstances, organizational objectives, and internal and external environmental and cultural factors that vary from one case study to another. However, there is a need to generalize certain marketing practices and principles that have been approved by a vast majority of scholars. Such marketing principles include but are not limited to improving the brand image by fulfilling corporate social responsibility, incorporating innovation and diversit y in the product design so that the product addresses the needs of a vast majority and diverse population of consumers, and selecting the right medium and the right time to advertise the products. Application of the marketing theory in practice requires understanding of difference between the role of advertisement and promotion. â€Å"[A]dvertising-like messages are used for longerterm strategic efforts to build brand awareness and attitude while promotion-like messages are designed for shorter-term tactical needs to stimulate an immediate sales response† (Percy, 2008, p. 28). Some of the hurdles in the integration of marketing theory with practice include lack of consistency between the organizational structure and the scope of work and organizational objectives, lack of involvement of

Monday, November 18, 2019

International Corporate Reporting Issues Essay Example | Topics and Well Written Essays - 2000 words

International Corporate Reporting Issues - Essay Example The Objective of Financial Reporting The major elements of the financial statements are the Asset, Liabilities, Equity, Income and Expenses. The financial statements are prepared on the accrual basis of accounting and ‘going concern’ concept both being the fundamental principles for recognition, measurement and reporting. The objective of financial reporting could be achieved only if the decision-usefulness aspect maintaining the principle of stewardship is fulfilled in financial reporting. The information provided should be useful to the existing investors and the other stakeholders and relevant in decision making. Qualitative aspects should enhance the financial statements’ usefulness in predicting the future while confirming the fair and true view of the current status of the company and the statements are required to be understandable and comparable. A - Decision Usefulness Stewardship information is historical in nature and they are subjected to various types of analysis to assess the performance during a particular year for taking decisions. The comparison of the information over a period of time reveals the trends in the operations and the business. But, in most of the cases these could not be extrapolated to assess the future of the company as they are dependent on various internal and external environmental factors. The other statements and the reports like Chairman’s Report or Directors’ Report to the shareholders would be useful in assessing the future performance. Information regarding Stewardship objective The data available from the Income Statement and the Balance Sheets are useful for working out various financial ratios for the purpose of analysis with reference to various parameters such as efficiency in performance, profitability, leverage, interest cover or return on capital employed. For example we can work out operating margin from the Consolidated Income Statement as below: 2011 2010 2009 Sales 13,232 12, 958 12,283 Operating Profit 2,595 2,574 2,418 Operating Margin 19.61% 19.86% 19.68% The comparison for the past three years suggests that though there is increase in sales during 2011 by 2.11% in 2011 and 5.5% in 2010 over the previous years it is not reflecting in gross margin. This is mainly because there has been slowdown in the economy during this period and there has been increase in excise duties, marketing and other operating expenses. Similarly, we work out the current ratio from the balance sheet. 2011 2010 Current Assets 7161 6952 Current Liabilities 4915 3944 Ratio 1.46 1.76 Though the current ratio is better than the generally accepted level of 1, the ratio has come down during 2011. This is mainly because of the increase in overdraft from 587 in 2010 to 1447 in 2011. Stewardship oriented cash flow statement would indicate the movement of cash in the operations of the business. The details given in the Annual Report serves the decision useful objective in the areas such as efficiency in working capital management or plough back of profits accrued for long term capital investments. Elliott and Elliott (p. 16) state â€Å"Cash flow accounting provides objective, consistent and prudent financial information about businesses transactions. It is

Saturday, November 16, 2019

Cleft Palate Microflora- Normal and Pathogenic

Cleft Palate Microflora- Normal and Pathogenic A REVIEW OF LITERATURE Abstract Oral cavity is a house for more than 300 species of microorganisms which includes aerobic, non aerobic, spores, fungi etc. Though many microorganisms are commensal only few microorganism involve in pathogenic process due to predisposing or initiative factors like poor oral hygiene, medically compromised patients, dentate and non dentate mouth, dietary habit, clefts, etc,. Cleft palate is one of the conditions in which commensal microorganisms can become pathogenic over time. There will be communication between nasal and oral microorganisms, which makes the habitat more suitable for few like Staphylococcus species. Even after the closure of due to exchange of microflora between oral and nasal cavity it can lead to wound dehiscence, which further leads to post operative complications. Key words: cleft palate, oral microflora, wound dehiscence, staphylococcus, streptococcus, commensal, fistula Introduction Clefts of the palate comprise a range of disorders affecting the oral cavity, the causes of which remain largely unknown1. Affected children have a range of functional problems which include feeding difficulties at birth due to problems with oral seal, swallowing and nasal regurgitation, hearing difficulties due to abnormality in the palatal musculature and speech difficulties due to nasal escape and articulation problems (Mossey and Little, 2009)2. Cleft may also predispose to alteration of normal flora at nose and oral cavity. Viridans streptococci were the first persistent colonizer of the human mouth and Streptococcus, Staphylococcus, and Neisseria spp were consistently found toward the end of the first year of life (Arief et al, 2005)3. NORMAL ORAL MICROFLORA The world we live in contains unimaginable numbers of bacteria, representing the major diversity of life on our planet. The commensal bacteria are present on the epithelial surfaces of the skin and on the mucosal surfaces of the oral cavity, respiratory tract, esophagus, gastrointestinal tract and urogenital tract. An estimated 300 to 500 bacterial species (sp) coexist within the oral cavity, of which approximately 50% are currently uncultivable.4 In spite of this, only a relatively small number of bacteria cause infection in man (Henderson and Wilson, 1998)5. Establishment of a normal flora occurs in a sequential manner: (1) the first exposure of the mucosal surfaces of a sterile neonate is to the maternal genital microflora during its passage through the birth canal, (2) a few hours later the organisms from the mothers (or the nurses) mouth and possibly a few from the environment are established in the mouth, usually Streptococci spp, which bind to mucosal epithelium, (3) oral flora on the childs first birthday usually consists of Streptococci, Staphylococci, Neisseriae and Lactobacilli, (4) the next evolutionary change in this community occurs during and after tooth eruption when two further niches are provided for bacterial colonization, (5) when all the teeth are lost as a result of senility, bacteria that colonize the mouth at this stage are very similar to those in a child before tooth eruption6,7,8. The oral cavity, upper respiratory tract, and certain regions of the ears and eyes have an indigenous microflora. Because of the close anatomic relationship of these structures, the resident flora of these regions shares many common pathogens. Within a given microenvironment, however, certain microbes that constitute the normal flora are associated with distinct anatomic sites. Thus, the normal flora exists within complex ecosystems at different sites and interacts closely with different bacterial spp and with the host epithelial layers. This indigenous microflora is known to change over time and host age, congenital malformation, underlying disease and chemotherapeutic agents affect its composition4. Microbial counts have been reported to vary from day to day9. A variety of conditions affect successful colonization of the mucosal surface in the oral cavity, including factors such as epithelial cell turnover, salivary flow, reduction in the oral pH environment following food intake and dentition. The predominant components of oral flora are Streptococcal spp, most commonly members of the Streptococcus group4,7,8. Increasing the amount of sugar intake would encourage growth of certain Streptococci that are able to tolerate a lower pH environment and also presence of teeth (Arief et al, 2005)3. Organisms generally considered as commensals including palate are coagulase-negative staphylococci, nonhemolytic and viridans streptococci, Corynebacterium spp, Neisseria spp Candida spp and other cultivable and not-yet-cultivable spp of Streptococcus.10,11,12 Candida albicans (C. albicans) is the most prevalent yeast isolated from the human body as a commensal or as an opportunistic pathogen13. The presence of C.albicans in the oral cavity is not indicative of disease. In many individuals, C.albicans is a minor component of their oral flora, and they have no clinical symptoms. In healthy individuals, a large number of sites in the oral cavity can be colonized by C.albicans14. A number of bacteria which populate the normal oral microflora are opportunistic pathogens capable of injuring or even killing the carrier, if conditions permit- organisms like Staphylococcus aureus (S.aureus), ÃŽ ²-hemolytic streptococci, Neisseria meningitides, Streptococcus pneumoniae,5 Klebsiella spp, Escherichia coli (E.coli) and Pseudomonas spp (Roscoe and Hoang, 2007)10. (Table 1) MICROFLORA INVOLVED IN WOUND DEHISCENCE Any wound is at some risk of becoming infected. One school of thought is that the density of microorganisms is the critical factor in determining whether a wound is likely to heal. However, a second school of thought argues that the presence of specific pathogens is of primary importance in delayed healing, while yet others have reported microorganisms to be of minimal importance in delayed healing15. Wound contaminants are likely to originate from three main sources: (i) the environment; (ii) the surrounding skin; (iii) endogenous sources involving mucous membranes. The normal microfloras of the oral cavity are both diverse and abundant, and these supply the vast majority of microorganisms that colonize wounds15. Bacterial infections after cleft palate surgery increase the risk of wound breakdown, palatal fistulas, poor speech, poor growth, poor aesthetic results and death. As the commensal oral bacteria in a normal young child change from birth as the child grows, factors that affect oral bacterial colonization include presence of antibodies that inhibit bacterial adherence, presence of teeth, formation of a biofilm, bacterial load in the saliva of attendants and frequency of exposure, prolonged hospital care and exposure to antibiotics (Chuo and Timmons 2005).3,16,17 The risk of infection is generally based on the susceptibility of a surgical wound to microbial contamination. Clean surgery carries 1 to 5% risk of postoperative wound infection and in dirty procedures that are significantly more susceptible to endogenous contamination, a 27% risk of infection has been estimated15. Though, infection is not a very frequent complication following correction of the palate, when infection occurs, partial or complete dehiscence may be the consequence. All wound infections were diagnosed on the second to sixth postoperative day while most patients leave the hospital on the third postoperative day. However, the strong relationship with preoperative cultures and dehiscence indicates that pathogens causing infection do play a role. Moreover, patients with dehiscence showed pus and fever, both signs of an infectious complication18. One might also argue that wound tension contributes to dehiscence and other causative factor. For example, too close to the incision edges may prevent the tissue from meeting and binding together properly. Sutures that are too tight can result in strangulation of the wound edges and poor blood supply to the wound, causing necrosis or sutures are removed too early.18 Wounds undergo a predictable alteration in microbial flora over time. Early on, the wound is colonized particularly by ÃŽ ²-hemolytic Streptococci and S.aureus, within the first 1 to 4 weeks, these are soon accompanied by that often infect wounds together in a synergistic fashion. After approximately 4 weeks, chronic wounds are more likely to become colonized by Pseudomonas spp Infections in older wounds are polymicrobial mixtures of aerobic pathogens usually associated with tissue necrosis, undermining and deep structure involvement (Gordon Dow, 2009).19 Invasive group A Streptococcal infections, once thought to be mainly a problem of the preantibiotic era, continue to be reported in many countries. In a multicenter general practice study in Denmark (1983 and 1984), group A ÃŽ ²-hemolytic streptococci detected in the throats of 10.9% of 99 asymptomatic children younger than 15 years old. Also the throat carrier rates of groups A, C and G ÃŽ ²-hemolytic streptococci decreased with increasing age of the individuals’ studied.16 The carrier ship of group A Streptococcus may predispose to infection and S.aureus ranks second among spp cultured from infected wounds18. Whilst the importance of Staphylococci as medical pathogens has been recognised for many years, it is now suggest that Staphylococci can be isolated frequently from the oral cavity of particular patients group such as children, elderly and in ill patients. Therefore, it is apparent that the oral cavity may present a hitherto poorly recognised reservoir of Staphylococci, some of which may, under appropriate conditions cause local or systemic infection.17 Nasal bacteria may be transmitted through an oronasal cleftfistula to the oral cavity, and it may be able to survive in the oral environment in children with cleft lip and palate (CLP) (Mims et al., 1993). S.aureus were identified in 53.1% of saliva samples and 40.6% of nasal samples. The oronasal fistula area was significantly higher in children who had S.aureus colonization in their oral cavity (Tuna et al, 2008).20 Recent data have shown that S.aureus is more frequently found in the oral flora of cleft patients than in normal children. Using saliva swabs, Arief et al. found that children with cleft palate showed more colonization by S.aureus compared to normal children of 3–39 months, which decreased significantly after operation.3 According to Aziz, Rhee, and Redai (2009), 5.5% of patients had nonlife-threatening complications (infection or wound dehiscence)21 and according to Hupkens and group (2007), they encountered 6.0% of wound dehiscence.18 The microbiological studies comparing flora between cleft and non-cleft sites in children with CLP by Brennan et al. (2001) determined that the oral bacteria colonize the cleft nasal floor in patients with unilateral oronasal fistulas. They reported that oral bacteria were not cultured in the nasal floor of the cleft in the majority of patients with oronasal fistula. The Investigators claimed that oral bacteria might occur only when the fistulae are sufficiently large to maintain a similar environment to the oral cavity.20 The study by Tuna et al. showed bacterial transmission was proven for large oronasal fistulas and a correlation was found with S.aureus counts in the children with CLP. It appears that as fistula size increases, significantly higher colony numbers of S.aureus were found in saliva samples. In addition, S.aureus tends to survive in the oral cavity as a result of transmission through the nasal passages as long as an unrepaired cleft exists.20 One study by Myburgh, and K.W. Butow (2009), swabs taken from their soft palates were made for days 0, 2, 4 and 6. The pathogenic organisms were: C.albicans, E.coli, Klebsiella pneumoniae, S. aureus, Pseudomonas aeruginosa and others.22 Another study from Finland showed that, Viridans Streptococci were the first persistent oral bacteria in babies (Kononen, 2000). Staphylococci were prevalent in more than 25% of children aged 0 to 6 months. The prevalence of Staphylococcus was lower in older children.16 Klebsiella spp are ubiquitous in nature and probably have two common habitats, one being the environment and the other being the mucosal surfaces of humans which they colonize. In humans, Klebsiella pneumoniae is present as a saprophyte in the nasopharynx and in the intestinal tract. Klebsiellae are opportunistic pathogens, can give rise to severe diseases such as septicemia, pneumonia, UTI, soft tissue infection and nosocomial outbreaks. The detection rate in the nasopharynx range from 1 to 6%, which differ considerably from study to study; Klebsiella spp are rarely found there and are regarded simply as transient members of the flora.23 According to the statistics of the Centers for Disease Control and Prevention, Klebsiella spp account for 8% of endemic hospital infections and 3% of epidemic outbreaks. The mortality due to Klebsiella spp bacteremia approaches 27–34% in adult patients. This data also showed a marked overall increase in the incidence of this infection during the study period and are in agreement with previous reports regarding the dynamics of gram-negative and Enterobacteriaceae bacteremias.24 During the 1980s and 1990s, the frequency of nosocomial Candidiasis has increased dramatically. Data from the USA National Nosocomial Infections Surveillance System shows that C.albicans was the most frequently isolated fungal pathogen (59.7%) in hospital environments. Transfer of Candida between individuals often occurs via the hands of health care workers, and nosocomial transmission can occur without Candidiasis outbreaks.14 Approximately 60% of the isolated recovered were gram-positive cocci (coagulase-negative Staphylococcus, ~31%), S.aureus (20%), and Enterococcus (9.5%). Over the past 5–10 years, most commonly isolated were gram-negative rods, such as E.coli, Klebsiella pneumonia, P.aeruginosa, and Enterobacter spp.23,25 It could be hypothesized that patient characteristics are primarily responsible for these differences. For example, genetic predilections, underlying diseases, social factors and economic factors and also differences in the virulence of individual microorganisms may be responsible for the manifestations of infection observed in cleft palate patients after surgery.26 (Table 2) Conclusion S.aureus and ÃŽ ²-hemolytic Streptococci are the commonest microflora which are responsible for wound dehiscence, it is always advised to do preoperative and postoperative culture. Though wound dehiscence is not always but frequent complication patient should be under proper care especially children. Alongside attention should be give to the other commensal microflora like Klebsiella, Candida, etc., which can become pathogenic over time in cleft patients. Despite advances in preoperative care, the rate of surgical wound dehiscence has not decreased in recent years. Recognition of risk factors, prevention of wound infection and mechanical stress on the incision are important. Management of dehisced wounds may include immediate surgery. If surgery is not needed, management is essentially the same as that of any other wound through maintenance of a moist wound environment, reduction of bio burden and pain, and promotion of granulation tissue.