Pengukuran Kecepatan Putar Motor Berbasis Programmable Logic Controller (P L C) Omron CPM2A Dan Komputer

PLC (Programmable Logic Control) banyak dipakai dalam dunia industri sebagai unit kontrol utama pada mesin-mesin produksi. PLC merupakan sekumpulan saklar elektronik yang dapat diatur kapan harus ON dan kapan harus OFF sesuai dengan hukum-hukum kontrol logic yang telah diprogram. Salah satu keunggulan dari PLC adalah dapat digunakan menjadi Alat Pengatur mesin yang berlainan hanya dengan mengubah program yang ada dalam PLC tanpa harus mengubah perangkat kerasnya. Pada penelitian ini akan dirancang bangun penggunaan PLC untuk menggerakkan motor DC 12 Volt Sekaligus membaca kecepatan putarnya (RPM) dengan menggunakan sebuah piringan yang berlubang yang akan dibaca oleh sensor LDR

Effect of Flush Existence, NAA and GA Application on Cocoa Pod Development

This experiment was carried out to study the photosynthate allocation between flush and young pods, and the effect of (naphthalene acetic acid) and (gibberellic acid) application to sink strength. Two cocoa clones KW 163 and KW 165 located in Kaliwining Experimental Station of Indonesian Coffea and Cocoa Research Institut were used on this experiment. Each clone was treated with flushes and without flush. Beside that, the young pods sprayed with NAA 250 mg L-1, GA 250 mg L-1, NAA 250 mg L-1 dan GA 250 mg L-1 and control (K = without NAA and GA). There were 2 x 4 treatment combinations for each clone, and replicated three trees for each combination. The parameter were cherelle wilt percentage, sucrose content, fresh and dry weight, long and diameter of healthy and wilting pods.The result showed that sink strength of young pods was lower than that of flushes, which caused application photosynthate translocation to the young pods was lower. NAA and GA application to the pods could improve sucrose allocation, increased pod weight and cherelle wilt was suppressed. The lack of photosynthate on young pod cause metabolism change, so pod became cherelle wilt. But, there was still not known the optimum concentration and method of application of those growth regulators to obtained minimum cherelle wilt

Effect of shot size in surface improvement via shot peening; analytical, modeling and experimental approaches

This paper discusses about the surface engineering improvement by means of shot peening. Shot peening improves the surface engineering quality by eliminating the tool marks, such as machining, grinding, stamping and other surface defects. Most importantly, the improvements of shot peening are produced by combination of compressive stress and cold work. Compressive stresses are beneficial in increasing resistances to fatigue failures, while the cold work effects of shot peening treatments can increase the surface hardness. It employs a steel shot media running at high speed to smash the material’s surfaces systematically, which results in a compressed and condensed surface. Several factors influence the effectiveness of shot peening. They are namely shot nature, shot size, shot hardness, Almen intensity, shot angle and coverage. The focus of this research is finding the influence of the shot size. The approaches used are analytical, computational, and experimental studies. The center of the study is the influence of shot size in the generation of the compressive residual stress. Through analytical, computational and experimental approaches, it is confirmed that the shot size has influence on the depth of the peak residual stress rather than the surface residual stress. This research reaffirms the qualitative understanding with quantitative and comprehensive approaches that can also be used for further in depth research in surface engineering improvement especially via shot peening

A model for cathodic blister growth in coating degradation using mesomechanics approach

The paper presents a novel theoretical model of blistering initiation and propagation especially useful for coating life assessment. The focus is on initially circular blisters. A two-part theoretical analysis of blistering is conducted using mesomechanics approach coupling diffusion concepts with fracture mechanics concepts. The diffusion concept is used to treat the corrosive species transport, eventually causing corrosion and blistering, while the fracture mechanics concept is used to treat the blister growth as circular crack propagation. Effects of thickness ratio and modulus ratio on blistering propagation are discussed. A simple criterion is identified which excludes the possibility of widespread blister propagation. Furthermore, a comparative study with the existing blistering models is carried out. Experiments are reported for blistering using a model coating-substrate system, chosen to allow visualisation of interface and to permit coupled (diffusion and residual) stresses in the coating over a full range of interest. The predicted limits from theoretical model are expected to be useful for the manufacturers in the design and deposition of coatings

Effect of autoclave sterilisation and heat activated sodium hypochlorite irrigation on the performance of nickel-titanium rotary files against cyclic fatigue

The present study aims to assess the impact of heat-activated sodium hypochlorite (NaOCl) and/or autoclave sterilisation on the cyclic fatigue resistance (CFR) of heat-treated nickel-titanium rotary files used in root canal treatment. The CFR of One Curve (OC) files was evaluated under the following conditions: as received (Group 1; control), immersion in NaOCl at 23 ± 1ºC (Group 2), immersion in NaOCl at 60 ± 1ºC (Group 3), autoclave sterilisation at 135 1ºC (Group 4), combined treatment of autoclave sterilisation and immersion in NaOCl at 23 ± 1ºC (Group 5), and combined treatment of autoclave sterilisation and immersion in NaOCl at 60 ± 1ºC (Group 6). A simulated root canal in a zirconia block was utilised to test the performance of the files. All the types of treatments resulted in significant reductions in fracture resistance of the OC files. Immersion of the files in NaOCl at 23ºC revealed the smallest reduction, while combined treatment of autoclaving and immersion in NaOCl at 60ºC caused the greatest reduction. Autoclave sterilisation or exposure of OC files to 2.5% NaOCl adversely affect the cyclic fatigue life and increasing solution temperature or combined treatment caused additionally significant reduction in CFR