Effect of Accelerator Addition on the Drying Time, Thickness and Glossy Clear Coat in Vehicle’s Body

Painting is the application of paint in liquid form onto the object, to create a thin layer which is then dried to form a hard layer or layers of paint. Many things are influential in the painting process, including the clear coat process which functions as a gloss effect and protects and maintains the paint color of the vehicle. In this research, it was expected to know the effect of the ratio between the thinner and accelerator on the clear coat on drying time, thickness, and glossiness of the clear coat. In this study, the mixture ratio variations of accelerator and thinner used were 0%: 100%, 25%: 75%, 50%: 50%, 75%: 25%. The speeds of drying with the aforementioned ratio of accelerator and thinner were 28 mins, 24 mins, 18 mins, and 16 mins respectively, while the values of the thickness of the ratio were 53, 4 µm, 55.6 µm, 54.03 µm, and 57.1 µm respectively, and the glossiness values of the accelerator and thinner with the ratio were 96.1 Gu, 95.4 Gu, 92.5 Gu, and 93.1 Gu respectively.

A Modified Pressure–Sinkage Model for Studying the Effect of a Hard Layer in Sandy Loam Soil

The applicability of the typical pressure–sinkage models used to characterize the soil’s bearing properties is limited to homogeneous soils (infinite thickness) that have no hard layer. At a given depth, a hard layer can have a considerable impact on the soil’s load-bearing capacity. It is thus necessary to alter the pressure–sinkage equation by taking this condition into account when assessing the load-bearing capacity. The present paper aims to determine a simple, high-fidelity model, in terms of soil characterization, that can account for the hard layer affection. To assess hard layer affection in this paper, a plate sinkage test (bevameter) was conducted on sandy loam soil. To this end, the soil was prepared by considering three bulk densities and two soil thickness levels at 7–9% moisture content levels. According to the results, this paper put forth a new perspective and related equations for characterizing bearing performance. The sinkage modulus (k) is an intrinsic soil parameter that has a determined unit of N/cm2 and is significant for managing the bearing performance. The results showed that the new modulus sinkage model incorporates the main factor of the rigid layer effect involving high fidelity that the conventional models have failed to account for.

STUDI MANFAAT DAYA DUKUNG BELLED PILE DAN MULTI-BELLED PILE

Foundation is a part of a structure which has a function for to resist and distribute the structure load on it to the soil. The greater load of structure resisted by the foundation make the greater uplift capacity needed. In the pile foundation the bearing capacity be affected by skin friction of the pile and end-bearing resistance, therefore one of the alternative for increase bearing capacity of the pile foundation is by use belled pile or multi-belled pile. Belled pile and multi-belled pile was a modification from the bore pile. The concept of belled pile is enlarge the size of the base pile with purpose to increase end-bearing resistance of the pile. In multi-belled pile enlarge size happen more than once, the enlarge size happen in the hard layer soil so this alternative will be suitable to applied in the soil that have a thin layer hard soil in the middle. In this study will be explained about bearing capacity behavior of the bore pile, belled-pile and multi-belled pile. The bearing capacity and volume of concrete of three type of pile will be compared. So the result of this study will show how efficient the use of multi-belled pile compared by straight bore pile. Fondasi adalah sebuah bagian dari stukrtur yang berfungsi untuk menahan dan menyalurkan beban bangunan yang ada diatasnya ke tanah. Semakin besar beban bangunan yang ditahan fondasi maka semakin besar pula daya dukung yang dibutuhkan fondasi. Pada fondasi tiang daya dukung fondasi dipengaruhi oleh gesekan selimut tiang dan tahanan ujung tiang sehingga salah satu cara untuk meningkatkan daya dukung fondasi adalah dengan menggunakan belled pile atau multi-belled pile. Belled pile dan multi-belled pile merupakan hasil modifikasi dari fondasi tiang bor. Konsep dari belled-pile sendiri adalah memperbesar ukuran penampang ujung tiang sehingga diharapkan tahanan ujung dari tiang akan meningkat. Pada multi-belled pile perbesaran penampang terjadi lebih dari satu kali yaitu pada lapisan tanah keras sehingga sangat cocok untuk diaplikasikan pada lapisan tanah yang memiliki lapisan keras tipis di bagian tengah. Pada penulisan ini akan dibahas mengenai perilaku daya dukung fondasi tiang bor biasa, belled pile dan multi-belled. Daya dukung dan volume beton yang digunakan dari ketiga jenis tiang tersebut akan dibandingkan. Sehingga hasil studi ini akan menunjukan seberapa efisien pengunaan belled-pile dan multi-belled pile dibandingkan dengan fondasi tiang bor biasa.

Brittle Fracture of Stainless Steel Dissimilar Metal Welds in the Upper Shelf of the Brittle-to-Ductile Transition Range

Stainless steel dissimilar metal welds (SS DMW) are widely used within the French nuclear power plants where they connect the main components (pressure vessel, pressurizer, steam generator) made of low alloy ferritic steel to the primary circuit pipes made of austenitic stainless steel. Because of their heterogeneous microstructure and mechanical properties, these junctions are critical components for the structure integrity and their fracture resistance has to be demonstrated for all the nominal or accidental operating conditions. This work aims at building a model to evaluate the risk of brittle fracture of the SS DMW in the upper shelf of the brittle-to ductile transition range. The observation of the microstructures around the fusion line revealed a martensitic layer and a fully austenitic zone, which undergo an important carbides precipitation during the post-weld heat treatment and form a narrow hard layer of carburized martensite and austenite. Fracture toughness tests were then carried out on CT specimens in the brittle-to-ductile temperature range and helped identify the MA interface (between martensite and austenite) as the weakest region in the SS DMW because of an intergranular fracture mechanism initiated at the carbides-rich interface. This mechanism was consistently observed for specimens with fatigue precrack fronts in the hard layer. To model the brittle behavior of the MA interface, the stress distributions on the MA interface were calculated with FE numerical simulation of the fracture toughness tests and a 1D 3 parameters Weibull model based on a threshold stress and a threshold length was identified for the CT specimens. The temperature dependence of the model parameters was finally studied and the effect of temperature on the intergranular fracture mechanism of the MA interface was explored.

Взаимодействие ферромагнитных слоев через магнитную перемычку

Using the methods of micromagnetic modeling, the dependence of the structure and energy of a domain wall localized in the magnetic bridge between ferromagnetic films on the geometric parameters of the system has been investigated. The effect of displacement and change in the shape of the magnetization curve of the soft magnetic layer caused by the exchange interaction with the magnetic hard layer through a magnetic filament has been demonstrated.

Penentuan Kadar Protein dan Karbohidrat pada Limbah Batang Pohon Pisang Kepok (Musa paradisiaca normalis)

The aim of this study was to determine protein and carbohydrate levels contained in waste of banana kepok (Musa paradisiaca Normalis) trees. Samples were taken from Mpanau Sigi Central Sulawesi. This study used Kjeldahl method in determining protein level, and anthrone method in determining reducing sugar level. The analysis results obtained in the hard layer of banana tree are 3.05% of protein level and 6.75% of carbohydrate level, while in the soft layer of banana tree are 0.08% of protein level and 4.75% of carbohydrate level, respectively. This study concluded that protein and carbohydrate levels obtained from the hard layer of banana kepok trees waste is higher, than literatures.

Rebuilding of coils of screw conveyors with chromium cast iron hard layer

The purpose of the work was to determine the possibility of rebuilding of the screw coils upper surface of a screw conveyors welded previously with chromium cast iron. The variant of surfacing directly on the residues of the hard layer and with the buffer layer was considered. The technology of hardfacing the coils after removal of the hardening upper layer and the technology of welding of new elements with the use of EnDOtec DO*390 powder wire has been developed to provide a NanoAlloy structure with boron nanocarbons in the iron matrix.