Journal of Science Technology (JoSTec)

Control Inventory of Raw Materials Using Supply Probabilistic with Q Method (Continuous Review Method) in the Animal Feed Industry Shrimp

Rinto Sihotang, Rina Handayani — Tue, 20 Feb 2024 00:00:00 +0000

The ingredients used to make shrimp feed include soybean meal, shrimp head meal, squid flour, wheat flour, fish head meal, and other components. The demand for companies to produce shrimp feed varies and is unpredictable, leading to a shortage of raw materials and the inability to fulfill orders. To solve this problem, the company places special raw material orders or surprise orders. However, sudden orders result in higher inventory costs than normal company orders. This study aims to determine the optimal raw material order, to minimize inventory costs through a probabilistic model of raw material inventory control with the Q method (continuous review method). Based on the results of the Q method, optimal order quantity (q), reorder points (r), and safety stock (Ss) were obtained. The total inventory cost generated in the Q method was lower than the total inventory cost used by the company, with a total savings of 6.11% per year.

THE INFLUENCE OF CURRENT STRENGTH ON THE TOUGHNESS OF JOINTS IN THE ELECTRODE ELECTRIC ARC WELDING PROCESS WRAPPED (SMAW) AISI 4340 STEEL

Andre Pratama, Julian, Supriono — Sun, 05 May 2024 00:00:00 +0000

The development of advanced construction technology cannot be separated from welding, as it plays an important role in constructing and repairing metal structures. At present, the construction of metal structures involves a lot of welding elements, especially in the field of good quality design. Based on the background, the problem can be formulated, namely, the effect of current strength on strength of Aisi 4340 steel joints after SMAW welding treatment. The research method used is the impact test method to see the results of the influence of strong currents in steel joints. The results of this study are the value of impact toughness at a current variation of 80 Ampere, the first specimen is 0.56080 J/mm2, the second specimen is 0.54811 J/mm2, and the third is 0.51724 J/mm2. The impact toughness value at 95 amps variation of the first sample is 0.01869 J/mm2, the second is 0.05481 J/mm2, and the third is 0.05172 J/mm2. From the test data, it can be seen that the average value of the average impact toughness in the variation of current strength of 80 Ampere and 95 Ampere is 80 Ampere current average impact toughness value of 0.54205 J/mm2 and 95 Ampere current average impact toughness value of 0.04174 J/m2. That the 80 ampere current variation is better and more efficient because it produces a higher toughness value than the 95 ampere current variation.

THE EFFECT OF CUTTING SPEED ON SURFACE ROUGHNESS IN THE TURNING PROCESS OF AISI 1045 CARBON STEEL USING KOBE M2 HSS CHISELS

Bersyeba Tarigan, Muksin Rasyid, Supriono — Sun, 05 May 2024 00:00:00 +0000

The purpose of this multilevel shaft turning performance is to analyze the specimen used, namely medium carbon steel alloy and get good workpiece results, knowing the ductility of the workpiece by adjusting the tool blade, speed, time, depth of cut, and surface roughness. The research method used is the impact test method to see the results of the influence of strong currents in steel joints. The results of this study are cutting speed is very influential on the results of the surface roughness of the test material, can be seen from the data analysis and research results. The surface of the test material with the highest level of smoothness is obtained from the use of the lowest cutting speed (100 m/min) with a roughness level of (4.1). The highest roughness level (7.1) with the cutting speed used (200 m/min). The higher the cutting speed used, the greater the price of the surface roughness value obtained or produced. However, the wear of the tool blade used is likely to also affect the level of surface roughness. Geram income depends on the cutting speed, the greater the feeding motion used, the greater the thickness of the resulting geram. The smaller the cutting speed used, the smaller the resulting furrow.

THE INFLUENCE OF THE TYPE OF BLADE MATERIAL IN THE BANANA STICK WASTE SHREDDING MACHINE ON THE QUALITY OF THE CHIPPED PRODUCTS

Muhammad Yamin, Joharsah, Muksin Rasyid — Sun, 05 May 2024 00:00:00 +0000

The banana gedebog waste chopper machine moves mechanically so that it cuts with a blade, the mechanical analysis of the machine consists of a chopper mechanism. For the analysis of choppers that use the main components, namely blades and shafts, while the driving mechanism is a supporting component such as electric motors, pulleys, and bearings. In analyzing the chopping machine aims to analyze the mechanical work of power and analyze the steps of each component work, analyze the results of the type of material usage of the blade. The driving engine power used is 94.57363 (watts) and the chopping force is 4.51375 x 10-6 (kg.m). The variation of rotation on the drive motor produces a variation of rotation on the chopping knife which has an average of good quality with the largest amount if using used blade material per car.

USE OF CONSTRUCTION WASTE IN MANUFACTURING ENVIRONMENTALLY FRIENDLY CONCRETE BRICKS

Muji Satrio, Syafriman Rivai, Ridwan Nasution — Sun, 05 May 2024 00:00:00 +0000

The purpose of this research is to evaluate the potential of construction waste generated by the construction industry as an alternative raw material in the manufacture of environmentally friendly concrete bricks. Research the method and process of concrete brick production using construction waste as the main raw material. Analyze the physical and mechanical properties of concrete bricks produced from construction waste and compare them with conventional concrete bricks. The approach used in this research is an integrated qualitative-quantitative approach. The qualitative approach was used to identify the characteristics and physico-chemical properties of the construction waste used. Meanwhile, the quantitative approach was used to test the quality of the concrete bricks produced. This research used an experimental design. Experiments were conducted in a construction laboratory with strict control of the variables that can affect the quality of concrete bricks. The result of this study is that the utilization of construction waste in the manufacture of environmentally friendly concrete bricks has been shown to enable a reduction in the use of natural raw materials and reduce the environmental impact of concrete brick production. The use of construction waste affects the quality of concrete bricks, including strength, durability, and other physical properties. This research provides an in-depth insight into how to optimally utilize construction waste without compromising product quality. The use of construction waste in concrete brick production can reduce the carbon footprint and other environmental impacts, helping to promote more sustainable construction practices.

THE EFFECT OF IMPLEMENTING BUILDING STRUCTURE AND CONSTRUCTION SYSTEMS ON ENERGY EFFICIENCY

Nasrullah, Muhammad Tayeb Mustamin — Mon, 13 May 2024 00:00:00 +0000

This research aims to investigate the effect of implementing structural systems and building construction on energy efficiency. Quantitative analysis methods are used with the help of SPSS Version 27 to test the correlation between structural system variables, building construction and energy efficiency. A linear regression test was carried out to understand how much influence the application of structural systems and building construction has on energy efficiency. The results of the research show that the application of the structure and building construction system has an effect on energy efficiency, where each increase of one unit influences the application of the structure and building construction system to 100% energy efficiency. In addition, the Pearson correlation test shows that there is a strong relationship between the application of structural systems and building construction and energy efficiency. A high correlation coefficient indicates that implementing the right system has the potential to increase building energy efficiency. These findings show the importance of selecting appropriate structural systems and building construction in achieving high energy efficiency. Thus, this research contributes to understanding how to build more energy efficient buildings.