Shallot Price Forecasting in Three Locations in Indonesia Using Generalized Space-Time Autoregressive Model

Shallots are one of the commodities that have an important role for the economy in Indonesia. Many shallot farmers, especially in production center areas, depend for their economy on shallot farming. The price of shallots in Indonesia during 2010-2022 fluctuated quite a bit. This is because the demand for shallots tends to increase over time, while shallot production is seasonal, and the distribution is uneven. The fluctuation of shallot prices and the huge costs of shallot farming result in risk and uncertainty for farmers. The forecasting method used is Generalized Space-Time Autoregressive (GSTAR). The results of the best model for predicting shallot prices in three locations in Indonesia, namely Cirebon, Tegal, and Madiun based on RMSE values, namely the GSTAR (31)-I(1) model use inverse distance normalization weights. Forecasting results for the highest shallot prices in Cirebon, Tegal and Madiun occur in the first week of August 2022. Meanwhile the lowest shallot prices in Cirebon and Madiun occur in the fifth week of August 2022, however the lowest shallot prices in Tegal occur in the fourth week of August 2022. Shallot price movement patterns in Cirebon, Tegal, and Madiun for the next 14 periods will continue to fluctuate but tends to show a downward trend. This was caused by several regions entering the harvest season, resulting in a spike in yields at the same time. As a result, the yield of shallots in the three locations was abundant and caused the price of shallots to decrease.

Performance Changes in Mass and Compressive Strength of High-Calcium Fly Ash Based Geopolymer Concrete Due to Sodium Sulphate Exposure

The sulfate environment is one of the conditions that significantly affect the durability of concrete. Sulfate attack causes cracks and affects the quality of the concrete. Therefore, it is necessary to innovate concrete that can withstand the aggression of this sulfate attack. Geopolymer concrete is a breakthrough that can be developed as an alternative material without using Portland cement as the ingredients, yet by using class F fly ash as the primary source material. On the other hand, the availability of class C fly ash with high CaO content is highly abundant in Indonesia. The high calcium content in this fly ash will cause the fresh geopolymer concrete to harden rapidly. Previous studies used sucrose as an additive to overcome this rapid hardening problem. However, its effect on the geopolymer concrete exposed to sulfate ingression requires further investigation. In this study, the geopolymer concrete was produced by using class C fly ash and sucrose. The sulfate ingression was simulated by immersing the concrete specimen in the sodium sulfate solution while the mass changes and compressive strength were examined. pH measurement of the sodium sulfate solution was also carried out to provide a different perspective on the data analysis. Cylindrical specimens, measuring 10 cm x 20 cm, were produced using the dry-mixing method and the characteristic strength of 28 MPa according to SNI 2847–2019. From the results, geopolymer concrete with sucrose showed a high workability performance through the high slump value obtained. Nevertheless, the experimental results also indicated the declining strength of geopolymer concrete after the sulfate exposure. However, only a slight reduction was observed. The strength residue still satisfies the minimum requirement of SNI 2847-2019. It shows the potential of geopolymer concrete to be used as a construction material in a harsh environment with high sulfate content

Implementation of Air Sweep to Prevent Blockages on The Salt Crystallization Process

In the process of crystallization salt, blockages often occur due to the large amount of salt that sticks to the wall’s hopper of the crusher machine. Seeing this condition, a Salt Cleaning Tool was designed using the air sweep method. In the first step of the design, a survey was carried out to find out how thick and the area of salt that sticks over a certain period. Furthermore, experiments were carried out to determine the position of the nozzle and the air pressure needed to knock out the salt attached to the hopper. The control system uses Arduino hardware as a micro controller tool. The experimental results require that the spray direction is tangential to the hopper surface, so the nozzle on the market needs to be modified. Likewise, an air pressure of 6 bar .is required and a burst time period of every 3 seconds with a nozzle opening time of 250 milliseconds with the condition that three solenoids are open together. Modification of the nozzle The control system uses Arduino hardware as a micro controller tool. The implementation of the air sweep as a salt cleaning tool has been successful, this is evidenced by operation of the crusher machine without problem

Technical Study of Ship Plate Firing Process Time with Variation of Deformation Values

In the process of shipbuilding production and repair, deformation is sometimes encountered due to several factors, starting from load pressure, pulling, lifting, and welding processes. A fairing process is carried out to overcome the plate deformation, in which the plate is heated and cooled simultaneously. The method used in this research is direct time measurement during the fairing process on test plate specimens with variations in the depth of deformation curvature. The data obtained, processed, and analyzed to obtain an estimate of the fairing processing time the longer the fairing process takes, following the equation Y = 41.285X + 530.94, where X is the deformation angle, and Y is the estimation fairing processing time area per half square meter

OBSAFER: Hydrogen Power Plant from Soybean Straw and Tofu Liquid Waste in Kediri District

Industrial developments result in higher consumption of electrical energy with considerable emissions. Efforts to develop alternative energy are carried out to overcome climate change. Hydrogen, as a clean energy, can be produced from biomass, such as soybean straw waste. The OBSAFER innovation was created to optimize the use of soybean straw and tofu liquid waste in electrical power. The process began with soybean straw waste pre-treated with NaOH and entered into a bioreactor for a dark fermentation process with Clostridium butyricum to produce hydrogen, methane, and carbon dioxide. Then, the gas is separated by a CH4 filter and a CO2 filter, so the main product is hydrogen. The OBSAFER technology can produce 821,751 kWh/year from 21.6 tons of soybean straw waste and Clostridium butyricum from tofu liquid waste

Design of an Integrated Temporary Storage for Hazardous and Toxic Material Wastes 4.0 Case Study in The Department of Industrial Chemical Engineering

The Department of Industrial Chemical Engineering is one of the departments within the Faculty of Vocation at Institut Sepuluh Nopember Surabaya (ITS). It has four laboratories. The activities conducted in these laboratories, both in terms of practical work and research, generate hazardous and toxic waste that should be stored in a temporary waste storage facility. Temporary storage is crucial for safely containing hazardous and toxic Hazardous waste until it can be properly processed, disposed of, or transported to a permanent storage location. The primary goals of this facility are containment, separation, safety, and compliance with environmental regulations. The design and features of the facility play a crucial role in ensuring the effectiveness of temporary storage. Secondary containment structures, chemical compatibility measures, ventilation systems, safety protocols, and emergency response equipment are the primary components of this facility. These elements work together to prevent leaks, control chemical reactions, disperse hazardous vapours, maintain safety, and enable rapid emergency response. This research provides knowledge on the design of temporary storage facilities for hazardous and toxic materials, with technical specifications following regulations. Effective temporary storage management can protect human health and the environment and promote sustainable waste management practices

Development and Analysis of an Innovative Precast Concrete U-Shell Beam

Precast concrete offers several advantages compared to conventional systems; precast concrete structure technology has become a strategy to enhance standardization, quality control, labor efficiency, and reduce environmental impact and construction pollution. The U-Shell precast beam is a reinforced concrete beam with a 'U' shape designed to enhance practicality and expedite the construction process as it does not require additional formwork and shoring during implementation. The U-Shell beam functions as a permanent formwork, and its design follows either monolithic or conventional methods. In multi-story buildings, using U-Shell beam can increase practical value, reduce costs, and improve time efficiency because they do not require additional formwork and scaffolding in the implementation application. This research involves the development of U-Shell precast beams, structure loading considering various loads, modeling using computer program to determine the structural reactions on each element, reinforcement design for the U-Shell beam structure, and analysis of the lifting and assembly of U-Shell precast beam. The building selected for reviewing U-Shell beams is the Building with a Special Moment Resisting Frame System. From the results of the analysis, the researcher drew several conclusions regarding the reinforcement design for the U-Shell beam under both conditions. In the condition before composite, the number of installed main reinforcements is 6 with a diameter of 13 mm, while in the condition after composite, the number increases to 8 with a diameter of 16 mm. Lifting reinforcement requires a diameter of 10 mm. The difference in reinforcement between before composite and after composite conditions is because before the composite the beam is still receiving self-load, whereas for the after composite condition the change in moment occurs. After all, the beam has received self-load and other loads. The development and analysis of an innovative precast concrete U-Sheel beam has complied with strength and serviceability

Performance based design of Hospital Building in Surabaya under variety design alternative using SNI 1726-2019 – Case study: Redesign Building

Nowadays, At the present time, the occurrence of regular earthquakes all over the world is turning into a significant problem. The structures that make up hospitals are among the most significant buildings in a living society because, in the event that a potentially dangerous scenario emerges, they help to serve as a caring and healing unit for the human population. A hospital building is made up of three different components: the structural component, the non-structural component, and the functional component. Each of these components can have an effect, either directly or indirectly, on the management and operation of the hospital building. Each time a natural or non-natural cause causes devastation and disaster, the globe suffers. In such cases, hospital buildings are vital in term of treating victims and injured persons, and housing those who lost their homes. Therefore, hospital facilities should be planned and constructed with enough stiffness and strength to resist disasters and serve as shelters or housing units afterward. This study analyses a hospital in area of Surabaya which built using Indonesian standard provision SNI 1726-2012. Weak structural members of the hospital are identified. The analysis determined to study the behaviour of hospital building when subjected to seismic forces using ETABS using current provision SNI 1726-2019. The investigation determined that the effect of the lateral forces under P-delta effect on the hospital building. Two different conditions have been compared, e.g., existing model and alternative configuration using dual system method to determining the recommendation for current building to resist seismic forces under new regulation. As a result, existing structure of hospital building still meet the requirements, but to fill the condition in accordance with SNI 1726-2019, some modifications need to be improved

The Effect of Aeration on Aerobic Biofilter Using Polyethylene Terephthalate Media for Chicken Slaughterhouse Liquid Waste

Chicken Slaughterhouse is one of the industries that process live chickens into ready-to-eat chicken meat products. Many chicken slaughterhouses still need liquid waste treatment technology and directly discharge it into the aquatic environment. RPA liquid waste has a high organic content that will cause environmental pollution with unpleasant odors and decay. This study uses an aerobic wastewater treatment method by utilizing aerobic microorganisms in wastewater that are attached to biofilter media to form biofilms. This study aims to reduce the concentration of COD, BOD, TSS, and ammonia and change the pH value of RPA liquid waste with aerobic biofilter treatment using honeycomb media from Polyethylene Terephthalate and to get the best aeration flow rate to reduce the concentration of pollutants from the aerobic biofilter reactor. In this study, the residence time and the addition of air discharge in the aeration process are varied. The results of this study show that there has been a decrease in the concentration of COD, BOD, TSS, and ammonia and changes in pH values following PERMENLHK No 5 of 2014 concerning the quality standards of slaughterhouse wastewater with the best aeration flowrate recommendation is 15 liters/minute

Characterization of Hydroxyapatite From Kupang Shells and Its Synthesis with Polycaprolactone for 3D Printing Filament

The number of deaths or fatalities due to accidents in Indonesia is increasing. In addition, traffic accidents can cause serious injuries such as damage to the skull. The bone implantation technique currently used is an autograft, but this technique has some limitations. This limitation of autograft can be overwhelmed with synthetic bone implants, one of which uses a mixture of Polycaprolactone (PCL) and Hydroxyapatite (HAp). A combination of HAp and PCL is recommended because the two materials complement each other's weaknesses and can increase elasticity and quality to produce suitable filaments for 3D printing processes. This study used hydroxyapatite from Kupang Shells by calcination and precipitation methods. Then do the test XRF, XRD, FTIR, and SEM to determine the quality. The results showed that HAp synthesized from Kupang Shells had potential characteristics as bone implants. Next, two methods were used to mix PCL with HAp as a 3D printing filament for bone implants: the dry and wet methods. After that, it is analyzed with SEM and Mechanical Strength. The results of the SEM test of HAp particles in the wet method have more even distribution and a smoother surface than in the dry method. The impact is visible on the filament's mechanical test, which shows better results in the wet method