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The presence of scattered waste in the environment has a significant impact on both environmental sustainability and human health. In Indonesia, the accumulation of waste has reached alarming levels, amounting to approximately 175,000 tons per day, or the equivalent of 64 million tons annually. Household activities are one of the main contributors, producing a wide variety of waste, including organic and non-organic materials. Poto Village is among the areas receiving particular attention regarding this issue due to the challenges it faces in waste management. Improper management of waste not only leads to air, water, and soil pollution but also increases the risk of various health problems within the community. One of the programs designed to address this problem is the 3R program, which emphasizes three main principles: reduce, recycle, and reuse. The purpose of this community service initiative is to improve public knowledge and awareness of effective waste management through the application of 3R practices. The activities were carried out in three main stages, namely preparation, education, and discussion through a question-and-answer session. The process began with a socialization activity that introduced the objectives, purposes, and sustainability aspects of waste management efforts in the village. The educational session was attended by 30 participants, consisting of housewives, farmers, and entrepreneurs, who represented key groups within the community. Furthermore, interviews with local cadres revealed that waste is collected weekly by garbage trucks, indicating the village’s commitment to environmental management. Participants responded enthusiastically throughout the educational sessions, showing a strong interest and positive reception toward the information provided. As a follow-up step, future activities could include hands-on training in waste management using available media and tools, which would allow participants to apply the concepts learned in a practical and sustainable manner.

Tawangsari Hamlet, Tejosari Village, Ngablak District, Magelang Regency, faces serious waste management challenges, reflected in the high daily waste production and the inactivity of waste banks post-COVID-19. To address this issue, the Tidar University Community Service Program (KKN) was implemented, aiming to improve environmental cleanliness through active community participation. This program also supports the achievement of the "Climate Action" goal in the Sustainable Development Goals (SDGs), which focuses on combating climate change caused by air pollution and reducing environmental pollution. The method used in this program is Participatory Action Research (PAR), which is oriented towards community empowerment by involving all stakeholders in every stage of implementation. The activity began with a series of observations to understand the condition of waste management in the community. Then, a waste management tool was created in the form of a smoke-free waste incinerator, which aims to manage inorganic waste in an environmentally friendly manner. In addition, trash bins to facilitate waste sorting at the household level were also provided. Socialization and mentoring for the community, especially youth organizations, were carried out to introduce and educate them on the correct use of incinerators and waste sorting. A demonstration of incinerator use was also conducted with the community, which proved to increase understanding and active participation. The implementation of the incinerator and waste sorting facility demonstrated that these measures were effective in addressing the waste problem in Tawangsari Hamlet and contributed to a cleaner and healthier environment. Furthermore, the program successfully raised environmental awareness among the Tawangsari Hamlet community. Through direct involvement in the waste management process, residents not only gained new knowledge about the importance of waste sorting but also experienced the direct benefits of implementing smoke-free incinerator technology.Keywords: waste management, low-smoke incinerator, Climate Action, SDGs, community empowerment, environmental pollution, Magelang Regency

This study aims to analyze the factors that affect passenger satisfaction at the airport through three main perspectives, namely: service, technology, and operations. The approach used is a literature study of ten scientific journals that discuss airport service quality from various aspects. The results of the study show that service quality, especially those covering SERVQUAL dimensions such as reliability, responsiveness, empathy, assurance, and physical evidence, plays a major role in shaping service user perceptions. The technology perspective, through the implementation of self-service such as self check-in, Flight Information Display Sistem (FIDS), and digital service applications, is proven to increase efficiency and convenience, even contributing up to 96.8% to user satisfaction according to one study. Meanwhile, from an operational perspective, aspects such as queue time at check-in counters, public facilities, and accessibility to the terminal also have a significant impact on the overall passenger experience. The conclusion of this study emphasizes the importance of integration between the three perspectives in designing strategies to improve airport service quality. Suggestions are given to airport managers to continue to improve services, expand technology adoption, and reorganize operations to create a safe, comfortable, and satisfying travel experience for all service users

Traffic congestion in Jakarta has become a serious problem, affecting various aspects of life, such as time efficiency, environmental quality, and economic productivity. As one solution to overcome this problem, the Jakarta government is developing a mass public transportation system, including the Light Rail Transit (LRT). The LRT is expected to reduce congestion by providing a more efficient and environmentally friendly transportation alternative. In the process of planning and optimizing the LRT system, discrete mathematics, particularly graph theory, plays a very important role. Graph theory is used to model the LRT station network and track, with vertices representing stations and edges representing connecting lines between stations. With this model, various analyses can be performed to optimize the LRT line, such as finding the shortest path between two stations or evaluating the connectivity between existing stations. The use of graph theory allows the identification of more efficient routes, resulting in faster travel and reduced passenger waiting times. In addition, graph theory also plays a role in optimizing the LRT route by minimizing the number of transfers between stations or avoiding passenger congestion at certain stations. With proper route and network optimization, the LRT can make a significant contribution to reducing traffic congestion in Jakarta. Furthermore, the development of an efficient public transportation system also supports improved air quality and reduces reliance on private vehicles. Overall, the application of graph theory in LRT system planning is a strategic step towards creating more efficient and sustainable transportation in large cities like Jakarta. Beyond route optimization, graph theory is also very useful in analyzing route capacity and passenger distribution along the LRT system.

Home industries are small- to medium-scale production units operated within or near households, typically relying on family members or a limited local workforce, with modest capital and without large-scale industrial technology. In furniture production, the main outputs are household items such as chairs, tables, wardrobes, beds, and shelves, while by-products include sawdust and unused wood pieces. Airborne pollutants— particularly wood dust (PM₁₀ and PM₂.₅) from sanding and cutting, along with fumes from paints, solvents, and adhesives—pose significant short- and long-term health risks to workers. This community service project, in collaboration with higher education institutions, aimed to establish long-term control measures. Initial steps involved measuring PM₁₀ and PM₂.₅ concentrations and assessing workers’ blood oxygen levels. Using a descriptive approach, workplace conditions were compared before and after work. Findings revealed a correlation between dust levels and blood oxygen saturation, supporting recommendations for long-term occupational health interventions.

In general, attacks on hospitals are prohibited under international humanitarian law (IHL), which aims to protect the life and health of civilians during armed conflicts. However, in certain circumstances, hospitals may lose their protection and thus become legitimate targets in warfare if they are considered to be involved in military activities or supporting the parties to the conflict. This brings into question the application of the principle of proportionality, which is an essential element of IHL. The principle of proportionality seeks to balance military necessity with the protection of civilians, requiring that the harm caused by military operations should not be disproportionate to the military advantage sought. This principle demands that military operations be conducted carefully to minimize harm to civilians and civilian objects, including hospitals. However, its application raises significant ethical questions regarding the moral justification of such actions, especially when hospitals are targeted in attacks. One prominent example that raises ethical concerns about this justification is the destruction of Al-Shifa Hospital in Northern Gaza. The hospital was destroyed in an airstrike during the conflict, causing severe harm to the civilian population that relied on this facility. While the principle of proportionality is designed to limit damage, attacks on hospitals such as Al-Shifa raise questions about whether the actions taken were truly consistent with this principle, particularly when the military gain achieved does not seem to outweigh the damage caused to human life and vital infrastructure. This article aims to explore the conventional moral justification of the principle of proportionality in international humanitarian law and evaluate its application in the case of Al-Shifa Hospital, challenging the boundaries of the principle in practice.

In the digital era, conventional media such as radio face significant challenges due to shifts in media consumption behavior, particularly among urban youth who prefer digital platforms and social media. Jak 101 FM has adapted by utilizing Instagram digital media in an off-air program titled “Jak After School” to reach a broader audience and build a positive image. This study examines the public relations strategy of Jak 101 FM in managing Instagram as part of promotion and image enhancement using descriptive qualitative methods and Chris Heuer's 4C theory (context, communication, collaboration, and connection). Research findings show that Jak 101 FM's public relations strategy involves creative content production, utilization of Instagram's interactive features, collaborating with local communities and influencers, and building emotional connections with audiences. The “Jak After School” program become an effective medium that strengthens audience loyalty and maintains Jak 101 FM's existence amid digital media industry competition.

Batang Bungo River faces severe pollution from domestic waste and illegal gold mining, which has led to an increase in skin diseases and diarrhea among residents of Tanjung Gedang, exacerbated by poor physical-chemical water quality, including low pH and high levels of Total Suspended Solids (TSS) and Chemical Oxygen Demand (COD), all of which foster the growth of pathogenic microorganisme. This study aimed to identify bacteria and fungi present in Batang Bungo River water, characterizing their colony morphology and microscopic structures to understand the impact of pollution on microbial communities. The methodology involved serial dilution of water samples, followed by inoculation onto Nutrient Agar (NA) media using the pour plate technique, and incubation at 37°C for 24-48 hours. Macroscopic observations of colonies (color, shape, texture) were performed, and representative colonies were stained with crystal violet for microscopic observation at 1000x magnification to identify cellular and hyphal structures. The results indicated the presence of various microorganisms, including Gram-positive bacteria, filamentous fungi, and possibly protozoa, with colonies exhibiting characteristics such as off-white color, rough surfaces, and irregular edges. Microscopic examination after crystal violet staining revealed rod-shaped (bacilli), spherical (cocci) structures, and branched filamentous structures resembling hyphae, consistent with a mixture of bacteria and filamentous fungi. The identification of pathogens like Clostridium, Dermatophilus, and Escherichia coli in previous studies, coupled with the poor water quality, confirms significant microbiological and chemical contamination. Crystal violet proved effective as a stain for microscopic identification of microorganism structures. In conclusion, the water quality of Batang Bungo River is highly concerning and requires serious attention for monitoring and management to safeguard public health and the river ecosystem.  

This study aims to analyze the quality of domestic wastewater based on three main parameters: pH, ammonia, and Chemical Oxygen Demand (COD). The wastewater samples were collected from an industrial area, chosen for its role as a primary source of domestic waste that can impact environmental quality. The pH was tested using potentiometry, while ammonia and COD concentrations were measured using UV-Vis spectrophotometry, a precise method for analyzing these substances. The results showed that the pH values of the wastewater ranged from 6.68 to 10.28. This variation in pH reflects the acidity or alkalinity of the wastewater, with some samples being neutral to slightly alkaline. The ammonia levels detected ranged from 0.0654 to 0.3849 mg/L. While these levels are within the limits set by regulations, they indicate a significant presence of ammonia in the wastewater, which requires continued monitoring. However, the most striking finding was the COD levels, which ranged from 21.60 to 245.71 mg/L, with some samples showing very high values. High COD levels indicate a large presence of organic matter, which can lead to a decline in water quality. Some samples with COD values exceeding the threshold of domestic wastewater quality standards, as stated in Ministerial Regulation No. 68 of 2016, require additional treatment to reduce organic contamination. Overall, while the pH and ammonia values remain within safe limits, the high COD levels in some samples indicate that further treatment is necessary to reduce organic pollution. This study emphasizes the importance of routine monitoring of domestic wastewater to protect environmental quality and prevent broader negative impacts on aquatic ecosystems and human health.  

Sultan Thaha Airport, Jambi, is one of the airports that has implemented a digital Airport PAS application process through a website-based system. This application information system is designed to improve efficiency and effectiveness in the PAS (Personal Airport Security) application process, which was previously done manually. With this system, it is expected that the entire administrative process can run faster, more transparently, and minimize errors. The purpose of this study is to analyze the implementation of the e-PAS information system, and to identify obstacles that arise in its implementation in the work environment of Sultan Thaha Airport, Jambi. The research method used is descriptive qualitative, with a blackbox testing approach to test the system's functionality. Data collection techniques were carried out through direct observation, interviews with 3 PAS applicants and 6 operational officers, and documentation related to system use. The data obtained were analyzed through the process of data reduction, data presentation, as well as drawing conclusions and verification. Data validity testing was carried out using the source and technique triangulation method. The results of the study indicate that the implementation of the e-PAS system has run quite well. However, several technical challenges remain, hindering the smooth running of the process, such as disruptions to the data input system, challenges with information validation, and suboptimal or incomplete system features. These findings provide important input for system developers to make continuous improvements to ensure more effective and efficient services in the future. Improved training for staff is also necessary to ensure optimal system utilization. Furthermore, regular evaluations of system performance are mandatory to maintain consistent service quality.

Biodiversity is a combination of the number of species and the number of individuals of each species in a community, one of which is in the Lichen group. Lichen is a form of mutualistic symbiosis between fungi and algae that morphologically and physiologically form a whole unit to produce new, unique individuals. This organism has an important role in the ecosystem, such as indicators of environmental quality, nutrient cycles, and soil surface cover. However, data on the diversity of Lichen species, especially in Geothermal areas, is still very limited so that information on their distribution and composition in the area is not optimal. This study aims to analyze the diversity index of Lichen species in the Jaboi Hot Spring area, Sukajaya District, Sabang City. The study was conducted in June 2025 using a combination of exploratory survey methods to determine research stations and transect line boundaries, as well as purposive sampling methods for Lichen sampling. Data were analyzed using the Shannon-Wiener diversity index (Ĥ). The results showed that there were 17 Lichen species belonging to 11 families with a total of 2027 colonies found in all observation stations. The obtained diversity index value was Ĥ = 2.819214, which is recommended as moderate diversity. These findings indicate that although the Jaboi Hot Springs area has unique environmental conditions due to geothermal activity, it still supports a diverse range of lichen species. This information is expected to form the basis for further research on lichen ecology, biodiversity conservation, and its potential use in geothermal areas. Furthermore, the results of this study can make important contributions to environmental management and bioindicator-based ecosystem quality monitoring.

Natural resource management in Paccellekang Village, which includes rice paddies, plantations, and teak trees, remains suboptimal despite its significant potential, particularly the abundant wood waste. This wood waste largely originates from agricultural activities, plantations, and small-scale wood processing. Currently, this waste is often simply burned or dumped, potentially polluting the environment and causing air pollution. However, if managed properly, wood waste can be transformed into high-value products that can provide financial benefits to the community. This community service activity aims to empower farmer groups through training in processing wood waste into marketable products such as charcoal, liquid smoke, and wood flour. These products not only have economic value but are also useful in various sectors, for example, liquid smoke as a natural preservative, charcoal as an environmentally friendly fuel, and wood flour as an industrial raw material. The program implementation method uses a structured approach that includes initial observations to identify potential partners and needs, outreach to provide a comprehensive understanding of the program's objectives, and training in wood waste processing technology. Furthermore, intensive mentoring and evaluation of implementation results are provided to ensure program sustainability. The results demonstrated that the farmer group members understood the concept of productive wood waste management and demonstrated high enthusiasm for developing innovative products. This program successfully improved the community's skills in utilizing local resources while reducing the negative impact of waste on the environment. Thus, this activity contributed to increasing community income and supporting sustainable economic development in Paccellekang Village.

This study aims to analyze the factors influencing passenger satisfaction at airports through three main perspectives: service, technology, and operations. The background of this research is based on the increasing competition between airports in providing an optimal travel experience amidst the development of the aviation industry and the increasing passenger demands for service quality. This study uses a literature study approach by analyzing ten selected scientific journals that specifically discuss airport service quality from various perspectives. The results of the study indicate that the service perspective, specifically those encompassing SERVQUAL dimensions such as reliability, responsiveness, empathy, assurance, and tangibles, has a significant contribution in shaping the perception and satisfaction of airport service users. The technology perspective also plays a significant role, particularly through the implementation of self-services such as self-check-in, Flight Information Display Sistem (FIDS), e-gates, and digital service applications that simplify the travel process. One of the studies analyzed shows that the application of technology can contribute up to 96.8% to user satisfaction, indicating the significant role of digitalization in this industry. From the operational side, factors such as speed of service at the check-in counter, queue time management, completeness and cleanliness of public facilities, and ease of access to the terminal have an equally important influence. These findings underscore that passenger satisfaction is influenced not only by service quality at the point of direct interaction, but also by the smoothness of the overall operational flow. The study's conclusions emphasize the importance of integrating these three perspectives in strategic planning for airport service improvement.  

Environmental character education from an early age is a strategic step in developing a generation that cares about the natural world. Instilling this value is crucial in concrete ways so that children can understand and directly experience the benefits of protecting the environment. One effort undertaken is through a simple hydroponic learning activity involving children from TKS Kartika V 16. The activity was held once at the Samarinda State Agricultural Polytechnic with the support of lecturers as resource persons. Through a hands-on learning method, the children were introduced to how to grow lettuce and bok choy using a simple hydroponic system. The learning process included an introduction to tools and materials, an explanation of the planting stages, and plant care. Observations throughout the activity showed high enthusiasm among the children. They were actively involved, from preparing the planting medium, planting the seeds, to providing air and nutrients to the plants. This activity fostered a sense of care and responsibility for the plants they grew themselves. Furthermore, the children's fine motor skills were also demonstrated through activities such as arranging the planting medium, sowing the seeds, and assembling the hydroponic equipment. This activity not only developed individual skills but also taught social values such as cooperation and mutual assistance. Children learn to work in groups, help each other, and appreciate each other's roles in the planting process. This hands-on, hands-on approach has proven effective in strengthening environmental awareness in a fun and contextual way. Therefore, environmental education through hydroponics can be a practical, inspiring, and easy-to-implement learning medium for young children, while also serving as a concrete example of how character education can go hand-in-hand with the introduction of environmentally friendly technologies.

Limited sanitation facilities among street vendors, particularly those selling meatballs, chicken noodles, and porridge, often pose a problem that impacts food safety. One common practice is repeatedly washing bowls and spoons with just a bucket of water, followed by drying the utensils with a cloth. This contaminated water can transmit pathogenic microorganisms that cause foodborne illnesses, increasing the risk of health problems for consumers. This problem requires a practical solution that street vendors can implement, taking into account limited space, mobility, and operational costs. This community service activity used a pre-experimental design method with a simple technological engineering approach to improve the sanitation of tableware. The innovation developed was a portable bowl washer made from used mineral water gallons, modified to be mobile, efficient, and water-efficient. The manufacturing process included design, assembly, testing, and evaluation with street vendors. Success was measured by observing the level of cleanliness of the tableware before and after use, as well as assessing the level of satisfaction and ease of use by the vendors. The results showed that the implementation of this portable sanitation device increased the effectiveness of tableware washing, reduced the repeated use of dirty water, and minimized the risk of cross-contamination. Partnering vendors stated that the device is practical, lightweight, and doesn't disrupt their sales activities. They hope this innovation will be replicated by other vendors and that local governments will consider implementing it as a standard for mobile food sanitation. This effort will not only improve the hygiene of eating utensils but also contribute to preventing foodborne illnesses in the community.

This study aims to examine the use of cattle waste as organic fertilizer to minimize agricultural operational costs in Mrawan Village, Tapen District, Bondowoso Regency. Cattle waste, particularly manure, is an abundant local resource that has not been optimally utilized by the local community. The majority of farmers in the village still rely on chemical fertilizers, which are relatively expensive and have a negative impact on long-term soil health. Therefore, this program is designed to provide a sustainable alternative solution through an educational approach and community empowerment. The methods used in this activity include outreach, technical training, and direct assistance in the process of making organic fertilizer from cow manure. Education focuses on simple fermentation techniques, the composition of natural additives, and appropriate fertilizer application methods. Farmers are actively involved in every stage of the activity, so they become not only beneficiaries but also agents of change in environmentally friendly agricultural practices. The results of the activity indicate that the use of organic fertilizer from cattle waste can reduce the cost of purchasing chemical fertilizers by up to 40% in a single planting season. In addition, organic fertilizer has been shown to increase soil fertility, improve soil structure, and support healthier plant growth. Environmental impacts are also reduced, as livestock waste management is more controlled and does not pollute water or air sources. Therefore, utilizing cattle waste as organic fertilizer not only reduces environmental pollution but also provides an economic and ecological solution that benefits local farmers. This program is expected to become a model for empowerment that can be replicated in other areas with similar characteristics.

This study was conducted to analyze the effect of rainwater on the survival of koi fry. The background of this study is based on the increasing demand for koi fish which encourages breeders to improve the quality and quantity of fry production. However, the success of seeding is influenced by several factors, especially air quality such as temperature and pH. Rainwater is known to have less stable quality, especially due to its low pH value, so it is necessary to study its impact on koi fry. This study was conducted on November 25–28, 2024 in the Bossbaster experimental pond, Legok Nyenang Village, Kadudampit District, Sukabumi Regency. The media used were 15 plastic gallons, each containing 5 liters of air and 40 newly hatched koi fry. The experimental design used a Completely Randomized Design (CRD) with 5 treatment levels and 3 replications. Treatments included A (100% rainwater), B (75% rainwater + 25% well water), C (50% rainwater + 50% well water), D (25% rainwater + 75% well water), and E (100% well water). The results of the ANOVA test showed that there was no significant difference (P>0.05) in the survival value of koi fish fry in the five treatments. Thus, it can be concluded that the use of rainwater does not have a significant effect on the survival of koi fish fry. In addition, the results of water quality observations showed that all parameters were still within the standard quality range, except for the temperature which was slightly below the standard.

This study aims to analyze passengers' understanding of prohibited items at Terminal 2 of Juanda International Airport and evaluate the effectiveness of information delivery strategies implemented to support aviation safety and security. The research uses a descriptive qualitative method with data collection techniques such as observation, interviews, and documentation. The findings show that most passengers, particularly elderly individuals, still do not have a clear understanding of the difference between items allowed in the cabin and those that must be placed in checked baggage. Information regarding prohibited items is only discovered when passengers reach the security check area (PSCP), which is considered too late, causing panic and discomfort among passengers. The main factor contributing to the low level of understanding is the unstrategic delivery of information and the lack of engaging communication media. Although information about prohibited items is available through posters and announcements, these methods do not effectively attract passengers' attention. Passengers often overlook the information placed in less visible or strategic locations. This indicates that the current information media have not been effective in providing significant impact on passengers' understanding. This study recommends several steps to improve passenger understanding. The placement of more effective information media, such as eye-catching educational banners and 3D video displays at the departure entrance area, is expected to attract more attention from passengers. Additionally, the use of digital platforms, such as airport apps or social media, could be an effective way to deliver information to passengers before they arrive at the airport. With these strategies, passengers can better prepare and avoid potential mistakes during security checks, thus supporting the smoothness and safety of their flights.  

Panoramic radiography is an imaging technique that plays a crucial role in dental practice, particularly in supporting the diagnosis and treatment planning process. Image quality that does not meet diagnostic standards can lead to the need for repeat imaging. The high rate of repeat panoramic imaging at the Radiology Unit of Dr. Suhardi Hardjolukito Air Force Base Hospital (RSPAU) is an indicator of the need for further study of the causal factors. The purpose of this study was to identify the causes of repeat panoramic radiography examinations, calculate the percentage contribution of each factor, assess radiographers' understanding of optimal image quality criteria, and explore appropriate strategies to reduce the frequency of repeat examinations. This study used a mixed methods approach with quantitative and qualitative descriptive approaches. Data were collected through observation, interviews, questionnaires, and documentation during August–October 2024 at the Radiology Unit of Dr. Suhardi Hardjolukito Air Force Base Hospital. The sample included 15 radiographers for the questionnaire and 3 radiographers for the interviews. An analysis of 916 panoramic radiography examinations revealed 57 repeat cases, with a rate of 6.2%. The primary factors causing repeats were machine error (57.8%), followed by positioning errors (24.5%), artifacts (10.5%), human error (5.3%), and patient movement (1.8%). Radiographers' understanding of the criteria for good panoramic images was high, with 66.7% answering all questions correctly. The primary effort implemented to reduce repeat rates is the implementation of routine quality control of equipment. The high repeat rate, exceeding national tolerance limits, indicates the need for technical and procedural improvements. Routine quality control and material refresher courses are needed to reduce repeat rates and improve patient safety.  

Camshaft lift is an important parameter that determines the height of the valve lift, calculated from the valve position when it is completely closed to the fully open position. This component plays a crucial role in regulating the flow of the air and fuel mixture into the combustion chamber. This study aims to improve the performance of a 200cc 4-stroke motorcycle engine through camshaft lift modification, which is expected to affect the characteristics of engine torque and power. Modifications were carried out by designing two types of modified camshafts, namely series A and series B, as a comparison to the standard camshaft. The research method used is experimental testing using a dynamometer to measure engine torque and power at various speeds, ranging from 4,000 to 10,000 RPM. The data obtained were analyzed to determine the effect of each type of camshaft on engine performance. The test results show that the B series camshaft provides the most significant performance improvement compared to the standard and A series camshafts. At 7,500 RPM, the standard camshaft produces an average torque of 19.2 Nm, the A series camshaft 19.6 Nm, while the B series camshaft reaches 21.2 Nm. Meanwhile, at 10,000 RPM, the average power of the standard camshaft is recorded at 22.2 HP, the A series camshaft 24.1 HP, and the B series camshaft reaches 26.3 HP. This increase indicates that the camshaft lift modification is able to optimize the duration and height of the valve opening, so that the supply of the fuel and air mixture to the combustion chamber becomes more efficient. Thus, camshaft modification, especially the B series, is an effective and applicable solution in increasing the performance output of a 200cc motorcycle engine without having to make major changes to the overall engine structure.