Coseismic Stability Assessment of a Damaged Underground Ammunition Storage Chamber Through Ambient Vibration Recordings and Numerical Modelling

In the past decade, ambient vibration measurements found numerous applications on unstable rock slopes and developed into a powerful tool for site characterization of slope instabilities. In this study, for the first time ambient vibration measurements were applied to a rock mass strongly disturbed and damaged by subsurface explosions. The site above the ammunition storage chamber at Mitholz (Switzerland) is especially interesting because the subsurface geology below the seismic array is well known, including the location of the caverns, and the degree of degradation caused by the subsurface explosions in 1947 of around 40 t TNT of ammunition. Measurement data were analyzed using current state-of-the-art seismic single-station and array methods, focusing on surface-wave dispersion analysis, wave field polarization, wave amplification using site-to-reference spectral ratios and analysis of normal mode behavior. The results allow for calibrating the elastic properties of a 2D numerical rock mechanical model which was used to simulate the stability of the disturbed rock mass during seismic loading. Therefore, ambient vibration measurements can contribute not only to a better understanding of the subsurface, but also for the assessment of earthquake risk.

Design and Development of Environmental Friendly Sub-Baric Storage Bin

Developments in vacuum storage technology present an opportunity to achieve significant improvements on protection, preservation and storage of agricultural commodities for residential and commercial use. Sub-baric storage is a environmental friendly, non-residue organic technology which provides chemical-free and insect contamination-free products. Due to creation of vacuum, there is a change in the environment inside the storage structure. This study therefore contributes an important knowledge and method in the development, fabrication and application of a sub baric storage bin (SBSB) as a best alternative to the commonly used traditional and modern storage structure. In its embodiment, the work focuses on the design and fabrication of the sub-baric storage bin to provide efficient storage of food grains by preventing the use of pesticides and insecticides and to reduce material loss during storage, a sub-baric storage bin of 500 kg capacity was designed and developed. The developed storage bin consists of storage chamber (500 kg), Vacuum pump, suction blower, grain inlet with pipe for loading, grain outlet for unloading, vacuum gauge, thermocouple, control panel, agitator, air filter, two inlet valves for gas infusion, vacuum release valve and SS mobile skid. The designed sub-baric storage bin is cylindrical in geometry with conical shape at bottom side and flat circular plate on top side and the storage bin has capacity of 500 kg to store food grains with hopper angle of 60°. The storage bin was designed in such a way that, it has provision for both bulk and bag storage and to work from 0-650 mm Hg vacuum. The developed SBSB was subjected to hydraulic pressure test and vacuum drop test to ensure a safe operation. It was observed that there was no implosion (compression) or explosion confirming to the fact that the design was adequate and also safe to operate. Also, there were no signs of bulging, buckling or any deformations observed in any of the components or the pipe lines, connections, fixtures or fasteners. Hence, it was concluded that the designed equipment could be operated safely at 650 mm Hg vacuum pressure satisfying all the applicable safety assurances and standards relevant to the industry.

Intermittent temperatures in the conservation of ‘BRS Kampai’ peaches

This study aimed at evaluating the quality of peaches borne by the cultivar BRS Kampai when cooled at intermittent temperatures throughout storage. They were stored at 1°C and relative humidity between 80% and 90% in a cold storage chamber. The following treatments were applied: T1 - fruit stored at 1±0.5°C; T2 - fruit stored at 1±0.5°C and increase in temperature every five days to 25°C; and T3 - fruit stored at 1±0.5°C and increase in temperature every seven days to 25°C. Fruit were submitted to increase in temperature when they were withdrawn from the cold storage chamber and kept in a heated room. Evaluations were conducted when fruit were harvested, after 10 cold storage days and 2 days of commercialization simulation at 25ºC (10+2) and after 20 cold storage days and 2 days of commercialization simulation at 25ºC (20+2). Peaches were evaluated in terms of mass loss, pulp firmness, soluble solids, titratable acidity, pH and epidermis color. T1 exhibited higher mass loss, higher soluble solid content and higher pulp firmness after 20 cold storage days, by comparison with the other treatments. T2 led to lower mass loss after 20 cold storage days than the ones of the other treatments. However, T2 also showed higher loss of pulp firmness in the same period. The use of intermittent temperatures throughout storage of ‘BRS Kampai’ peaches may be an alternative to extend their post-harvest period.

DEVELOPMENT, FABRICATION, AND PERFORMANCE EVALUATION OF INDIRECT MULTI-PORTIONED TYPE SOLAR DRYER FOR AGRICULTURAL PRODUCE

OBJECTIVE: The primary objective of this study was to minimize post-harvest damages and improve the handling of agricultural commodities. The secondary objective was to assess the performance of the dryer by varying inlet velocity of air on temperature, final moisture of the product, drying period, and drying rate METHODS: The present research was carried out for the development, fabrication, and testing of a multi-portioned type solar dryer. The multi-portioned dryer consisted of a collector unit, air storage chamber, drying cabins, and a chimney. A fan assembly was also attached at the inlet of the collector and at the outlet of the drying compartment to control the air velocity and to remove the moist air. RESULTS: The data obtained from the experiments revealed that the maximum temperature elevation of 36.5oC was attained during a no-load test. The results obtained after carrying out load tests revealed that the maximum drying rate of 47 g/hr was achieved at the air inlet velocity of 3.2 m/s. The initial moisture content of 80.50% was brought down to 3.31% in five sunshine hours of 150 gram sliced potatoes. Each portion received air at varying speeds, and it was observed that the portion receiving air at the lowest speed had the maximum temperature. CONCLUSION: The lowest temperature elevation was recorded for the portion receiving air at the highest speed. The dryer was also found to be suitable for the on-field practical application for the drying of perishable commodities.

Ozone treatment on cucumber and tomato during simulated retail storage

The effect of storage temperature and ozone treatment on the post-harvest quality of cucumber and tomato was investigated. Cucumber and tomato were stored together with or without gaseous ozone treatment at 20 °C and 14 °C for 16 days. Firmness, color, weight loss, DA index and decay percentage of samples were evaluated during storage period. The results showed that the combination of ozone treatment and cold storage could maintain the quality of these horticultural products and decreased the decay incidence. Additionally, this combination also reduced the weight loss of samples during storage. Furthermore, ozone treatment maintained the green skin color of cucumber. No sign of chilling injury occurred during storage at 14 °C. Commodities stored with approximately 0.1 ppm gaseous ozone at 14 °C retained the firmness compared to other treatments until the end of the experiment. This study suggests a promising use of gaseous ozone treatment in storage chamber where ethylene-producing and ethylene-sensitive vegetables are stored together.

Zero-Energy Cool Chamber in Anthracnose Disease Management of Postharvest Capsicum frutescens

Anthracnose caused by Colletotrichum gloeosporioides is one of important diseases causing postharvest losses on chili. This study aimed to determine the effectiveness of the zero energy cool chamber (ZECC) in reducing the severity of anthracnose in Capsicum frutescens L. and extending the shelf life of chilies. The research was started by designing and building ZECC as a storage area for chilies. Chilies with and without fungal inoculation were stored in ZECC and storage chamber at room temperature. C. gloeosporioides experienced a growth inhibition of 40.48% after being stored in ZECC compared to its growth at room temperature. Storage of chilies in ZECC was able to reduce the severity of anthracnose by 56.2% on the 15th day, did not affect vitamin C content and total dissolved solids (TSS) and was able to reduce chilies weight loss during storage. Based on the organovisual test using the visual quality rating method and the Hedonic sensory test, consumers prefer chilies stored in the ZECC. The results showed that storage in ZECC could extend the shelf life of chilies. This storage model does not use electricity or is zero energy so it can be used by small scale farmers. This is the first report on the use of ZECC for the management of anthracnose in postharvest chilies in Indonesia.

Numerical Analysis on the Storage of Nuclear Waste in Gas-Saturated Deep Coal Seam

Nuclear power has contributed humanity a lot since its successful usage in electricity power generation. According to the global statistics, nuclear power accounts for 16% of the total electricity generation in 2020. However, the rapid development of nuclear power also brings up some problems, in which the storage of nuclear waste is the thorny one. This work carries out a series of modeling and simulation analysis on the geological storage of nuclear waste in a gas-saturated deep coal seam. As the first step, a coupled heat-solid-gas model with three constitutional fields of heat transfer, coal deformation, and gas seepage that based on three governing conservation equations is proposed. The approved mechanical model covers series of interactive influences among temperature change, dual permeability of coal, thermal stress, and gas sorption. As the second step, a finite element numerical model and numerical simulation are developed to analyze the storage of nuclear waste in a gas-saturated deep coal seam based on the partial differential equations (PDE) solver of COMSOL Multiphysics with MATLAB. The numerical simulation is implemented and solved then to draw the following conclusions as the nuclear waste chamber heats up the surrounding coal seam firstly in the initial storage stage of 400 years and then be heated by the far-field reservoir. The initial velocity of gas flow decreases gradually with the increment of distance from the storage chamber. Coal gas flows outward from the central storage chamber to the outer area in the first 100 years when the gas pressure in the region nearby the central storage chamber is higher than that in the far region and flows back then while the temperature in the outer region is higher. The modeling and simulation studies are expected to provide a deep understanding on the geological storage of nuclear waste.

Application of the Riccati hereditary mathematical model to the study of the dynamics of radon accumulation in the storage chamber

The article proposes a mathematical model of radon accumulation in a chamber, which takes into account the hereditary properties of the environment in which radon migrates. The model equation is the fractional Riccati equation with a derivative of a fractional variable order of the Gerasimov-Caputo type, taking into account heredity, as well as taking into account nonlinearity, which is responsible for the mechanisms of radon entry into the chamber. The obtained model curves of the accumulation process are compared with real data. It is shown that the model described in the work gives a better agreement between the model and real curves of radon accumulation and can be used for a more accurate description of the processes occurring in the chamber.

A Thermo-Hydro-Mechanical Coupling Analysis for the Contaminant Transport in a Bentonite Barrier with Variable Saturation

The migration of hazardous substances in a bentonite barrier layer is a key issue for the safety of nuclear waste storage. This study develops a thermo-hydro-mechanical coupling model to simulate the contaminant migration in a bentonite barrier layer of the nuclear waste storage chamber. In particular, the Richard’s equation is used to describe the groundwater flow in the bentonite barrier layer with variable saturation. Thermal diffusion and concentration diffusion are coupled with the layer deformation and fluid flow. The migration rate and diffusion range of hazardous substances in the bentonite barrier layer are numerically simulated. These numerical simulations show that the heat release from nuclear waste can induce a temperature gradient and deformation, and thus significantly affects both transfer rate and concentration distribution of dilute substances. These multi-physical couplings under different initial saturation may significantly modify the sealing efficiency of an unsaturated bentonite barrier layer and thus this model is of great significance in the safety evaluation of a nuclear waste disposal repository.

KAJIAN POTENSI EKSTRAK BUAH MENGKUDU (Morinda citrifolia) SEBAGAI DESINFEKTAN ALAMI TERHADAP JAMUR PADA RUANG PENYIMPANAN SUSU

Morinda citrifolia can be used as a natural disinfectant on the milk storage space because it has an anti-fungal compound. The purpose of this study is to determine the potential of Morinda citrifolia extract as a natural disinfectant to fungi in the milk storage room, is reviewed from a decrease in the number of mushrooms and identification of the type of fungi before and after the use of Morinda citrifolia extracts. The study was conducted experimentally using a complete random design (CRD) with four treatments of P0 (without using Morinda citrifolia), P1 (15% concentration of Morinda citrifolia extract), P2 (20% concentration of Morinda citrifolia extract), P3 (concentration 25% of Morinda citrifolia extracts) and six times the replay. The observed is a decrease in the number of fungi, identifying the type of fungi before the use of Morinda citrifolia extract, identification of the type of fungi after the use of Morinda citrifolia extract. The results showed that Morinda citrifolia extract had a noticeable effect on decreasing the number of fungi in the milk storage room, with a consecutive drop percentage of P0 = 25,12%, P1 = 58,12%, P2 = 61,89%, P3 = 70,59%. The result of identification of fungi type on milk storage Chamber is Cephalosporium sp, Aspergillus ochraceus, Aspergillus flavus, Penicillium purpurogenum, Penicillium digitatum, Mucor sp. The decrease in the amount of the type of each fungus is Cephalosporium sp (68,13%), Aspergillus ochraceus (88%), Aspergillus flavu (87,94%), Penicillium purpurogenum (85,71%), Penicillium digitatum (95.73%), Mucor sp (59,57%).