Numerical study of circle fractal grid perforated plate as a turbulent generator in combustion chamber

Fractal grids can be used to design turbulent flows with low power losses and high turbulence intensities for intense yet economic mixing over a region of designed length and location. The introducing circle grid perforated plate is the main aim of this present paper. In this numerical work, we want to ascertain a new approach in turbulence generators on the structure of premixes flames using perforated plate fractal-grids pattern. In this paper, we compared circle grid perforated plate by varies using its diameters, spacing and number of holes on the plate. The result showed good perceptivity of the fractal generated turbulence and the fractal flow physics. The turbulent intensity can be increased by a grid with higher blockage ratio

Open Reduction of the Isolated Anterior Frontal Sinus Fracture

AbstractThe anterior wall of the frontal sinus is extremely resilient to injury. Incidents involving high-velocity impact, such as motor vehicle accidents, gunshots and sports injuries, may result in frontal sinus fractures. Clinical symptoms are associated with location and the severity. The best way to diagnose with a combination of clinical examination and CT scan. The management is mostly based on open reduction and internal fixation. The objectives was the importance of doing right management in patients with frontal sinus fracture. Reported a case of maxillofacial multiple fractures (right frontal fracture + right maxilla fracture) in a 28-year-old man, performed open reduction and internal fixation. Frontal sinus fracture is a fracture generally occurs due to traffic accidents. Anamnese of patient complaints and symptoms, physical examination and 3D CT scan can help make the diagnosis, and surgeons should give attention to the management criteria to prevent complication.

STUDI PENELITIAN KUAT TEKAN BETON MENGGUNAKAN SERABUT KELAPA SAWIT DAN KAWAT IKAT

Penelitian ini bertujuan untuk mengetahui pengaruh beton dengan tambahan serat (serabut kelapa sawit dan kawat ikat) terhadap kuat tekan beton normal (0%), menggunakan metode eksperimen. Dengan bahan-bahan penyusun beton diantaranya yaitu kerikil, pasir kasar, pasir halus, air, semen andalas (porlant komposit type III), kawat ikat dan serabut kelapa sawit (yang berasal dari PT. Socfindo Kebun Seunagan). Benda uji dibuat berbentuk kubus (15 × 15 × 15 cm) dengan FAS 0,45. Variasi penambahan serat sebanyak 2% (serabut kelapa sawit) + 4% (kawat ikat) dan 6% (serabut kelapa sawit) + 4% (kawat ikat) dari berat semen. Pengujian kuat tekan dilaksanakan di laboratorium milik PT. Espe Makmur Beton untuk benda uji umur 7 hari (berjumlah 9 sampel benda uji) dan umur 28 hari (berjumlah 9 sampel benda uji) menggunakan mesin uji tekan beton (merek Indotest). Berdasarkan pengujian didapatkan hasil kuat tekan rata-rata untuk beton normal (0%) sebesar 16,67 Mpa. Serta untuk beton dengan tambahan serat variasi 2% (serabut kelapa sawit) + 4% (kawat ikat) didapatkan hasil kuat tekannya sebesar 9,70 Mpa terjadi penurunan sebesar 41,81% terhadap kuat tekan beton normal (0%) dan 6% (serabut kelapa sawit) + 4% (kawat ikat) didapatkan hasil kuat tekannya sebesar 4,96 Mpa terjadi penurunan sebesar 70,25% terhadap kuat tekan beton normal (0%). Maka dengan penambahan serabut kelapa sawit dan kawat berdampak negatif terhadap kuat tekan beton

Rekonstruksi Lantai Orbita dan Dinding Anterior Maksila pada Blow Out Fracture Terbuka Tidak Murni Menggunakan Titanium Mesh Plate

Blow out fracture merupakan fraktur yang melibatkan dinding orbita terutama dinding medial dan atau lantai orbita yang disebabkan dari peningkatan tekanan intraorbita mendadak. Blow out fracture merupakan fraktur orbita yang paling sering terjadi akibat jatuh, perkelahian, kecelakaan lalu lintas atau cedera olahraga. Tanda dan gejala yang dapat muncul karena blow out fracture adalah enoftalmos, diplopia, dan gangguan gerak bola mata. Diagnosis blow out frakture ditegakkan dari anamnesis, pemeriksaan fisik dan computerized tomography scanning. Tindakan bedah rekonstruksi menggunakan implan dilakukan jika didapatkan adanya herniasi volume isi bola mata, fraktur lantai orbita >1 cm,  muscle entrapment, diplopia, enoftalmus dan keterbatasan gerakan bola mata. Dilaporkan satu kasus fraktur blow out dekstra yang ditatalaksana rekonstruksi dengan menggunakan titanium mesh plate dan screws melalui pendekatan insisi luka infra orbita. Fraktur ini terjadi akibat benturan objek dari luar yang mengenai orbita atau rim orbita yang mengakibatkan peningkatan tekanan intraorbita. Tekanan intraorbita mendorong organ intraorbita ke sekelilingnya termasuk ke lantai orbita yang rapuh sehingga terjadi herniasi ke inferior.Kata kunci: blow out fracture, fraktur orbita, mesh titanium, trauma fasia

Exploring the Nature of Human Resource Management Practices at Family Businesses in Palestine

This article provides substantial and current information on HRM knowledge and practices in Palestine and particularly explore the nature of HRM practices at family businesses within Palestinian context.The population consisted of all Palestinian family businesses employ 50 employees and above. Data was collected by means of a written questionnaire sent to all Palestinian family firms.Questionnaires were distributed and interviews were conducted with managers including HR managers. Findings show that family firms are far away from applying HRM practices and some family firms apply it partially and sporadically. The study leads to a better understanding of family firms in Palestine.Recommendations to the owners and managers of family businesses to change the attitudes and values of family firm’s management staff through organization development sessions and techniques to devote more effort for human resources by applying human resource management practices.Key words: Human resource management practices; Family businesse

Hierarchical self organizing map and focusing inspection strategy for mobile robot novelty detection

Novelty detection is a process of recognizing changes based on learned knowledge. In this research, a novelty detection system was implemented on a mobile robot with an array of sonar sensors for surveillance application. In order to perform novelty detection, a map that stores normal information with respect to any particular robot pose in an environment is required. The map is needed to detect changes and determine the position of novel event. The challenges of mobile novelty detection system are that the false positive rate is usually high whereas the true positive rate is usually low due to mapping and monitoring problems. During mapping, errors due to robot localization and sensor measurement can reduce the quality of the map built. However, available methods in mapping assume perfect localization, hence error in localization is not taken into account in the process of mapping. During monitoring, inspection interval that is too small will consume a lot of time and energy but if the interval is too big, novelty could be missed, hence lower the true positive detection. On top of that, low true positive detection is also caused by the low reliability of sonar sensor measurement. Thus, the objective of this thesis is to utilize mobile novelty detection system by developing a mapping and monitoring strategy that has low false positive detection, high true positive detection and able to estimate the position of a novelty. This thesis proposed two methods regarding to mapping and monitoring process; a hierarchical Self Organizing Map (SOM) and a Focusing Inspection Strategy (FIS). Unlike other mapping methods, hierarchical SOM also consider localization error when associating the normal information with respect to the robot pose. FIS is a multi resolution monitoring strategy which works by changing the frequency of measurement depending on the detection of anomaly. In this thesis, two models were considered; a step (FS) and linear (FL) resolution models. The hierarchical SOM was validated by using simulation and experimentation of the inspection in environment with normal and novel event. False positive rate is measured to determine the map performance. The results show that hierarchical SOM is able to map the normal condition of the environment very well. The inspection results show the false positive rate occurred less than 0.1 at the higher sensitivity setting of 0.9 in either normal or novel condition. The performance of FIS was investigated by using experimentation of the inspection of novel objects of different sizes. The results show that by changing the frequency of measurement using the FS and FL models, the number of true positive detection increases up to 80% when compared to inspection with fix measurement frequency. FIS also reduced the error of position estimation by about 8.8% and 10.9% each for FS and FL and maintained the false positive rate lower than 0.1

Electricity biogeneration using microbial fuel cells approach

Renewable energies are very important because they released clean gasses to the atmosphere. Hence, polluted air and water can be prevented by using renewable energy sources to generate power. Nowadays, primary fuel sources, especially fossil fuels, are used in generation of the electric energy. However, generation of electricity by using these fuel sources gives negative effects on the environment and human health. It is because the power plants will release substances for air pollution such as carbon monoxide (CO), nitrogen oxide (NOx) and also sulphur dioxide (SO2). Besides, Greenhouse gases (GHGs) was produced when the fossil fuels are burned. It will lead to climate changes and degrade the environment..

Energy harvesting from pressured water flow with IoT monitoring

Energy harvesting are required in order to improve the green technology. Energy harvesting or also known as power harvesting is the process where the energy is gain from the outside source for example solar energy, heat energy, wind energy and kinetic energy. This energy can be collected and converted to a useful electrical energy. Harvested energy give a small amount of power for a low energy electronics. This is because the energy converted comes from the recycle of waste energy, example, heat energy that produced from the operation of engine