Pengaruh Arah Pemakanandan Sudut Permukaan Bidang Kerja Terhadap Kekasaran Permukaan Material S45c Pada Mesin Frais Cnc Menggunakan Ballnose Endmill

Nilai sebuah produk dapat diindikasikan salah satunya adalah kualitas permukaan. Bahan baja S45C banyak dipakai pada konstruksi mesin sehingga sering mengalami perlakuan proses pemesinan. Proses pemesinan mempunyai kualitas kehalusan (nilai kekasaran) yang berbeda terutama pada mesin frais CNC. Penelitian ini bertujuan untuk mengetahui pengaruh variasi arah pemakanan dan sudut permukaan bidang kerja pada proses mesin frais CNC pada material S45C menggunakan jenis alat potong ballnose endmill terhadap nilai kekasaran. Metode penelitian yang digunakan dengan memberikan variasi arah pemakanan searah 45°, searah 90° dan berputar konstan sumbu Z dengan variasi sudut permukaan bidang kerja sebesar sebesar 0, 30, 45 dan 60°. Pergeseran alat potong sebesar 0,3 mm berputar pada 3000 rpm dan feeding 429 mm/menit dengan kedalaman pemakanan 0,4 mm. Pengujian kekasaran hasil pemesinan menggunakan TR 100 Surface Roughness Tester dan diamati menggunakan mikroskop digital USB perbesaran 800x. Hasil yang didapat nilai kekasaran yang paling kecil (halus) adalah sebesar 0,85 µm terjadi pada arah pemakanan searah 45° bertemu dengan sudut bidang permukaan kerja 30°. Pada arah pemakanan searah 90° dan searah 45°nilai kekasaran semakin meningkat (semakin kasar) sebanding dengan bertambahnya sudut permukaan bidang kerja sedangkan pada arah pemakanan berputar konstan sumbu Z nilai kekasaran semakin menurun (semakin halus) berbanding terbalik dengan bertambahnya sudut permukaan bidang kerja

Pengembangan Wisata Bahari di Pulau Raas dalam Rangka Menggerakkan Perekonomian Lokal

This community service aims to improve the potential of the archipelago, especially from the marine tourism sector. Against the background of not optimal management of tourism potential in the District of Raas which is an archipelago and has potential places to become a tourist. Development of Marine Tourism on Raas Island in Order to Mobilize the Local Economy. The process of developing marine tourism is done by mapping, observation, community empowerment and literature study. Based on the results of mapping and observation shows that there are 3 beaches that have attraction and are very potential, just need to be developed again and also managed properly. The three beaches also have different characteristics so that if the tours offered are not monotonous. The conclusion of the process of developing marine tourism is the need for awareness of the local community and also the cooperation of various parties and also agencies to work together to develop and build supporting facilities that can support these three potential beaches into a marine tourism that is not only a power pull Raas District alone, but also can be a pillar of the people's econom

Evaluation of residential grid-connected photovoltaic system as the potential energy source in Malaysia

Application of solar energy in Malaysia has been started in 1998. This country has a large potential of solar energy due to its location at equatorial region. The current energy consumption and demand in Malaysia is describes in this paper. The potential of solar energy in Malaysia is described together with the suitable photovoltaic construction. It also explains the plans conducted by Malaysia involving solar energy that covers investments and also projects involved such as Malaysia Building Integrated Photovoltaic (MBIPV). Simulation of grid-connected photovoltaic system in this study is performed using HOMER software. Finally, the potential of having a grid-connected PV system in a residential area is analyzed. The positive and negative findings in terms of cost and suitability of the system are explained

Potential of Residential Grid-Connected Photovoltaic System as the Future Energy Source in Malaysia

Malaysia has started the implementation of solarenergy harvesting in 1998. Located at equatorial region, Malaysia hasa large potential for solar energy. This paper examines the currentenergy consumption and demand in Malaysia. The potential of solarenergy harvesting in Malaysia is described together with the suitablephotovoltaic construction. It also explains the plans conducted byMalaysia involving solar energy that covers investments and alsoprojects involved such as Malaysia Building Integrated Photovoltaic(MBIPV). Finally, this paper analyses the potential of having a gridconnectedPV system in a residential area. The positive and negativefindings in terms of cost and suitability of the system are explaine

Thermodynamic evaluation of a solar based kalina cycle

Solar energy has enormous potential in the world. It can produce energy generation several times larger than the overall world energy demand. However, a major challenge to implement it is the high costs of electricity generation from solar sources. These costs can be reduced by improving the conversion efficiency from solar energy to electrical energy. Currently, the Rankine cycle is the most frequently used power cycle for generating electricity from solar energy. An interesting alternative to the commonly used Rankine cycle that uses solar heat energy as its input is the Kalina cycle. The Kalina cycle uses a mixture of ammonia and water as its working fluid. When using a mixture of ammonia and water as a working fluid, temperature varies while heat is added and rejected during phase change. This theoretically would be more efficient than a power cycle who only uses water as its working fluid. This paper examines the performance of a Kalina cycle with solar energy from concentrating solar plant as the input heat. A solution algorithm is developed and programmed to evaluate the thermodynamic properties of a Kalina cycle with inlet turbine temperature of 400 °C. Parametric analysis was done to study the effects of turbine inlet pressure and turbine inlet ammonia concentration on cycle efficiency. Results shows that both parameters have a positive relationship with cycle efficiency. Turbine outlet pressure was found to be a major influence on cycle efficiency. Maximum efficiency was found to be 33% at a turbine inlet pressure of 140 bar and turbine inlet ammonia concentration of 0.8

Effectiveness of single dose oral dexamethasone versus multidose prednisolone for treatment of acute exacerbations of asthma among children

Asthma is one of the most common chronic diseases in children and worldwide its prevalence has increased dramatically in the last three decades. We aimed to compare single dose oral dexamethasone versus multiple doses of oral prednisolone in children with acute exacerbation of asthma in terms of post treatment requirement of systemic steroids. This Randomized control trial has been conducted in the Department of paediatrics, KRL Hospital, Islamabad from Dec 2018 to June 2019.312 patients between the age of 2-12 years patients were randomized into Group A receiving a STAT single dose of oral dexamethasone 0.3 mg/kg and Group B receiving prednisolone 1 mg/kg/day followed by two doses on Day 2 and 3. further dose of systemic steroids were ascertained through PRAM score. In this study mean age in Group A was 8 years with SD ± 5.68 while mean age in Group B was 7 years with SD ± 6.12. In Group A 58% patients were male and 42% patients were female. Whereas in Group B 59% patients were male and 41% patients were female. In Group A 12% patients had further requirement of systemic steroids while in Group B 18% patients had further requirement of systemic steroids while 82% patients didn't had further requirement of systemic steroids. Our study concludes that post treatment requirement of systemic steroids is less in single dose oral dexamethasone as compare to multiple doses of oral prednisolone in children with acute exacerbation of asthma. [Abstract copyright: © 2022 The Authors.

Radial basis function neural network for head roll prediction modelling in a motion sickness study

Motion Sickness (MS) is the result of uneasy feelings that occurs when travelling. In MS mitigation studies, it is necessary to investigate and measure the occupant’s Motion Sickness Incidence (MSI) for analysis purposes. One way to mathematically calculate the MSI is by using a 6-DOF Subjective Vertical Conflict (SVC) model. This model utilises the information of the vehicle lateral acceleration and the occupant’s head roll angle to determine the MSI. The data of the lateral acceleration can be obtained by using a sensor. However, it is impractical to use a sensor to acquire the occupant’s head roll response. Therefore, this study presents the occupant’s head roll prediction model by using the Radial Basis Function Neural Network (RBFNN) method to estimate the actual head roll responses. The prediction model is modelled based on the correlation between lateral acceleration and head roll angle during curve driving. Experiments have been conducted to collect real naturalistic data for modelling purposes. The results show that the predicted responses from the model are similar with the real responses from the experiment. In future, it is expected that the prediction model will be useful in measuring the occupant’s MSI level by providing the estimated head roll responses

Strength behaviour of kaolin treated by demolished concrete materials

Kaolin has claynite structure in nature, presenting several properties which may justify in many engineering and industrial applications. However, this type of soil is categorised as problematic soil because the presence of claynite properties eventually resulting the kaolin to have low shear strength and high compressibility as other clay soil. Due to that weakness, kaolinite does not meet the requirements necessary for any construction purposes particularly at the preliminary stage. Hence, to overcome this issue, soil stabilisation process is needed prior any construction works. The aim of this study is to determine the strength characteristics of stabilised soft clay soil (Kaolin S300) with demolished concrete materials (DCM). The selection of DCM as the stabilizer for the purpose reutilisation of waste materials that currently has been a great concern for the environmental sustainability. The percentages of DCM content used were 5%,10%,15%20%,25%,30% with varying curing time of 7days, 14 days and 28 days, respectively. Based on the result it was reported that, the unconfined compressive strength (UCS) test shows that the highest strength value obtained of 595.6 kPa kaolin treated with 30% DCM at 28 curing days. It is equivalent to 92% increment from the untreated kaolin sample at 0 days. However, the optimum amount of DCM which provides significant strength improvement was found when more than 20% of DCM is presented after 14 curing days. Hence, it shows the possible usage of DCM as waste material to effectively stabilize kaolin at specific amounts sufficiently

Cryptosporidium Priming Is More Effective than Vaccine for Protection against Cryptosporidiosis in a Murine Protein Malnutrition Model

Cryptosporidium is a major cause of severe diarrhea, especially in malnourished children. Using a murine model of C. parvum oocyst challenge that recapitulates clinical features of severe cryptosporidiosis during malnutrition, we interrogated the effect of protein malnutrition (PM) on primary and secondary responses to C. parvum challenge, and tested the differential ability of mucosal priming strategies to overcome the PM-induced susceptibility. We determined that while PM fundamentally alters systemic and mucosal primary immune responses to Cryptosporidium, priming with C. parvum (106 oocysts) provides robust protective immunity against re-challenge despite ongoing PM. C. parvum priming restores mucosal Th1-type effectors (CD3+CD8+CD103+ T-cells) and cytokines (IFNγ, and IL12p40) that otherwise decrease with ongoing PM. Vaccination strategies with Cryptosporidium antigens expressed in the S. Typhi vector 908htr, however, do not enhance Th1-type responses to C. parvum challenge during PM, even though vaccination strongly boosts immunity in challenged fully nourished hosts. Remote non-specific exposures to the attenuated S. Typhi vector alone or the TLR9 agonist CpG ODN-1668 can partially attenuate C. parvum severity during PM, but neither as effectively as viable C. parvum priming. We conclude that although PM interferes with basal and vaccine-boosted immune responses to C. parvum, sustained reductions in disease severity are possible through mucosal activators of host defenses, and specifically C. parvum priming can elicit impressively robust Th1-type protective immunity despite ongoing protein malnutrition. These findings add insight into potential correlates of Cryptosporidium immunity and future vaccine strategies in malnourished children