Ice Block Research Articles

Experimental Study on Multi Bubble Ice Breaking Under Layer Ice Boundary Conditions

Under certain conditions of bubble spacing and bubble to ice distance, the motion state and ice breaking effect of horizontal and vertical bubbles under ice plate boundary conditions were studied. Bubbles are generated through underwater discharge, and the generating device is placed horizontally or vertically below the ice plate, and the experimental phenomenon is observed through an ultra-high-speed camera. Firstly, the motion characteristics and ice breaking ability of two horizontal bubbles under an unperforated ice block were demonstrated. Then, the motion characteristics of two horizontal bubbles and two vertical bubbles under a porous ice block, the breaking effect of the ice block, and the water mound phenomenon on the free surface were observed. The experiment observed unique bubble behavior, including bubble fusion, bubble collapse, and oblique jet, as well as the influence of bubble-bubble and bubble-ice interactions on the morphology evolution and ice breaking effect of bubbles. The results indicate that the ice breaking effect of the interaction between bubbles and perforated ice plates is weaker than that of non-perforated ice plates, which may be more helpful for subsequent bubble ice breaking research.

Pengembangan Sistem Pendingin Cold Box Penyimpanan Ikan Dengan Pemanfaatan Pcm

One of the technologies in the refrigeration system to improve power and cost efficiency is to utilize technology to overcome this problem is to use phase change materials (PCM) to replace standard refrigerants. The purpose of this study is an attempt to reduce the operational cost of fish storage with a cold box cooling system for fish storage by utilizing PCM. The method used in this research is the experimental method. From the results of the study obtained data using a variation of 2 PCM compressor takes 219.7 minutes when mode ON for 7 hours of testing, variation 4 PCM compressor takes 202.7 minutes when mode ON for 7 hours of testing, variation 6 PCM takes 177.4 minutes when mode ON for 7 hours of testing. With this variation 6 PCMs are more optimal in helping to reduce compressor working time. The more the number of PCMs placed in the cold box can help reduce the compressor on/off cycle and the electrical energy required by the compressor is more efficient, the most efficient variation is the 6 PCM variation with a power efficiency of 15.31%. With the use of PCM can save operational costs up to 59.54% compared to using ice blocks. The design of cold boxes using PCM will benefit after 3 months of use compared to using block ice.

SAMSKARAH KARANAM MATAM WSR TO RASAPARPATI

Rasa Parpati is the type of Sagandha Parpati Kalpana. To prepare Parpati Kalpana, at least one ingredient should get liquefied at normal Heating and should get solidified when it gets cooled down, not only that, to get the thin flake Like structure specific pressure needs to be applied. In the present study Rasa Parpati was Prepared by using Samaguna Kajjali (equal quantity of Parada and Gandhaka) and to check the Cooling effect and the role of base platform; here three different platforms were made i.e., cow Dung and wet clay mixed platform, only wet clay platform (Earthen platform) and ice block Platform. Total nine samples of Rasa Parpati were prepared, three on each platform to check Which platform is convenient to prepare Rasa Parpati. The average thickness of Rasa Parpati Was found to be minimum (2.83mm) on cow dung and wet clay mixed platform whereas the Maximum (4mm) on ice block platform i.e., 4mm. Average thickness of Rasa Parpati made on Earthen platform was 3.57mm which is thicker than the Cow dung and wet clay mixed Platform and thinner than the ice cube platform. Which indicates the best platform to make Thinnest Parpati is cow dung and wet clay mixed platform.

Effect of leading-edge geometry on flow beneath a simulated ice block

ABSTRACTThe present article conducted detailed velocity measurements beneath simulated ice blocks with different leading-edge geometries (round, rectangular, upward and downward triangular). The results examined flow separation at the leading-edge, vortex generation, and subsequent vortex propagation. The instantaneous velocity field depicts an unsteady flow dominated by large-scale vortices, with the Kelvin–Helmholtz type instability dominating the shear layer interface. The mode of vortex generation and propagation was influenced by the geometry of the leading edge. These vortices were dominant for the rectangular and upward triangular configurations. Propagation of these vortices creates low-pressure zones beneath the simulated ice block, which can affect the ice block stability. For all ice blocks, the mean flow accelerated, due to flow separation, and this can result in fluctuations in the dynamic pressure field. These events can lead to greater under-turning moments, as well as the interfacial melting of the ice.

Experimental investigation of the accretion and shedding process on a heatable NACA0012 airfoil in ice crystal icing conditions

Ice crystal icing can lead to damage and flame-outs in the combustion chamber of an aircraft engine due to accretion and shedding of ice blocks. The present work aims at a better understanding of accretion and shedding phenomena by quantitatively analysing experimental investigations conducted at the icing wind tunnels of Airbus CRT and TU Braunschweig. Particular focus is laid on ice accretion and shedding resulting from ice crystal icing on heated substrates. Heatable NACA0012 airfoils were designed and tested in a broad range of parametric conditions. Generally, large ice accretions and large shed areas were observed on non-heated surfaces at positive wet bulb temperatures. On surfaces heated with a low heat flux the accreted area was larger, while with large heat fluxes mostly run-back of liquid water was observed. For the examined experimental conditions an ice accretion threshold existed beyond which there was continuous accretion or complete shedding. The experimental findings of this study not only consolidated previous studies in similar conditions, but also help identify new findings for heated surfaces at negative wet bulb temperatures and unheated surfaces with mixed-phase conditions at positive wet bulb temperatures. They form a large collection of new data on ice accretion and shedding and provide a comprehensive experimental database quantitatively analyzed for validating future physics based and numerical models.

Pengaruh Aerasi dan Suhu Nutrisi terhadap Sawi Samhong (Brassica juncea L.) dengan Hidroponik Rakit Apung

The floating raft is a simple hydroponic system, in which the nutrient solution stagnates without circulation, causing the condition of the dissolved oxygen content in the nutrient solution to be less than optimal for plant growth. To improve aeration can be done using an aerator and the addition of blocks of ice in the nutrient solution. This study aims to determine the effect of aeration using an aerator and temperature regulation of the nutrient solution on mustard samhong using floating raft hydroponics. There are two independent variables used, namely aeration (A) which is grouped into without aerator (A0) and with aerator (A1), and nutrient temperature (T) which is grouped into T1 (18o-20oC), T2 (22o-24oC), and T3 (26o-28oC). Data on plant height, number of leaves, and plant weight were analyzed using a two-way ANOVA test at the 5% level. The results showed that the aerator increased the dissolved oxygen content in the nutrient solution so that it had a better effect on plants, and the nutritional temperature that has the best effect is T1.

Ablation of a solid by an immersed jet

Issues related to the occurrence of a severe accident with melting of the core are considered as early as in the design phase of nuclear reactors. For sodium cooled fast reactors (SFR-Na), two mitigation devices are set up in the reactor vessel. The first one is ”transfer tubes” that are used to relocate the corium in the lower part of the vessel; these tubes are arranged in the fuel assembly. The second one is called ”core-catcher” and is supposed to receive the corium melt in the lower part of the reactor vessel. This device must absolutely be correctly designed to resist to the thermal ablation which undoubtedly will occur since the corium melt temperature is very high. In this context, experimental studies are carried out to fully understand the ablation process with simulating fluids, the final goal being to accurately simulate it in realistic conditions. Thus, an experimental study of a simplified situation is exposed using simulating materials: the core-catcher material is replaced by transparent ice and corium by a hot water jet. In this paper, the ablation of an ice block by an immersed water jet is investigated. Experiments were performed with an initial nozzle-to-solid distance H/Dj=10 and the Reynolds number ranged between ∼104 and ∼1.5×105. First, heat transfer is characterized at the stagnation point by analyzing pictures taken during cavity formation. In a second step, the cavity shape evolution is deeply analyzed to get more information about heat transfer in the whole cavity. These results help understanding the complex mechanisms at play during ablation and will be used to validate numerical simulations.

Numerical investigation of ice plate fractures upon rigid ball impact

The fracture process and breaking capability of ice cover impacted by high-speed projectiles before underwater explosion is an urgent subject of scientific research in ice engineering applications. This paper presents the results of numerical simulations of the dynamic fracture behaviour induced by the impact of a small spherical projectile on an ice plate. The proposed 3D rate-dependent peridynamics model is validated by the dynamic ring Brazilian disc testing of ice specimens. Good agreements between the present model and the previous experiments are obtained in ice breaking processes and damage patterns of thin, medium and thick ice plates. Several cases are analysed and discussed in terms of various impact velocities, ice thicknesses, and boundary constraint conditions. The simulations identify detailed fracturing characteristics that are not observed in experiments, including the sequence and shape of crack propagation in a short time interval, the crater formation and the damage evolution along the thickness direction. The proposed peridynamics computational model provides new understanding of the potential of using penetrator–ice block impact tests to observe the evolution of complex brittle damage and reveal the failure mechanism.

Using new cold chain technologies to extend the vaccine cold chain in India: Equipment performance, acceptability, systems fit, and costs

This study evaluated the performance, acceptability, costs, and systems fit of three new cold chain devices in India: a second-generation ice-lined refrigerator (ILR), a solar direct drive (SDD) refrigerator, and a long-term passive device (LTPD). The evaluation was conducted over 15 months during 2016–2017. Sites were selected for their diversity in climate, terrain, and grid electrical supply, and 31 cold chain devices were deployed, 1 to each site. Results showed that all three technologies maintained correct temperatures. The SDD refrigerators had no malfunctions, whilst the ILRs had at least one malfunction, mostly due to the printed circuit board’s sensitivity to the erratic power supply. The LTPD temperature display panel caused challenges initially that required replacement of all solar panels with lithium batteries. Yet the devices’ long holdovers helped ensure vaccine potency. One challenge, particularly with the ILRs and SDD refrigerators, was condensation. The passively cooled LTPD was valued in settings with smaller populations and unreliable or no power; however, some its features, including the need to condition ice blocks, made it challenging to operate. In addition, the acceptable temperature range for the LTPD, as for all passively cooled devices (greater than 0 °C and less than + 10 °C),was confusing for some health workers due to the decades-long emphasis on maintaining temperatures at + 2 °C to + 8 °C. The greatest system-related benefit was establishment of new cold chain points (CCPs) at locations with intermittent or no grid electricity, bringing immunisation services closer to hard-to-reach areas. A key limitation of all three devices was the inability to freeze ice packs, which are required for vaccine carriers, somewhat restricting the potential of these technologies to reach underserved populations. Moreover, establishing new CCPs added costs to the health system. Results from this study, including costing data, can help guide decision-making.

Parameters of Ice Blocks and Their Relationship with the Structure of Hummocks in the Kara, Laptev, and East Siberian Seas

Parameters of Ice Blocks and Their Relationship with the Structure of Hummocks in the Kara, Laptev, and East Siberian Seas

Ice melting in salty water: layering and non-monotonic dependence on the mean salinity

The presence of salt in seawater strongly affects the melt rate and the shape evolution of ice, both of utmost relevance in ice–ocean interactions and thus for the climate. To get a better quantitative understanding of the physical mechanics at play in ice melting in salty water, we numerically investigate the lateral melting of an ice block in stably stratified saline water. The developing ice shape from our numerical results shows good agreement with the experiments and theory from Huppert & Turner (J. Fluid Mech., vol. 100, 1980, pp. 367–384). Furthermore, we find that the melt rate of ice depends non-monotonically on the mean ambient salinity: it first decreases for increasing salt concentration until a local minimum is attained, and then increases again. This non-monotonic behaviour of the ice melt rate is due to the competition among salinity-driven buoyancy, temperature-driven buoyancy and salinity-induced stratification. We develop a theoretical model based on the force balance which gives a prediction of the salt concentration for which the melt rate is minimal, and is consistent with our data. Our findings give insight into the interplay between phase transitions and double-diffusive convective flows.

Almajiranci: A Challenge to National Development in Northern Nigeria

The study examined Almajiranci and its challenge to national development in northern Nigeria. Three research questions were raised and answered through descriptive survey using purely qualitative research design. The sample of the study is 44 Almajiri, their mallams, parents and community members from 2 Local Government Areas in Sokoto State. Structured interview was used for data collection, after which it was transcribed, coded and arranged in themes and sub-themes with detailed explanation. The study reveals that, Almajiris engaged in petty business and services like; nail cutting, selling potatoes, selling sugar cane, wheel-barrow services, selling perfume, shoe shiners (cobbler), selling date (dabino), farm labour or garden work, selling of pure water, selling of ice block, roasted groundnut, upload and unload goods, selling forage, mason, labourer, carpentry, tailoring, travelled to southern Nigeria for trade, selling shoes, sewing caps, sticker and leather, which could not contribute meaningfully to national development. Therefore, people are of the opinion that Almajiri Qur’anic Education should be accompanied by formal and or vocational education for them to contribute meaningfully to public service in northern Nigeria and Sokoto state in particular, because there is no much to say about the initiatives of Almajiris in Sokoto state. A significant number of the respondents believed that Almajiris have no initiatives. The study therefore recommended that, government should integrate Almajiri education into the mainstream formal education properly and proscribe the Almajiris from roaming the streets. Alternatively, there should be government intervention to re-organize Almajiri education in Sokoto state and Northern Nigeria in general, where functional skills and knowledge are acquired.

Round scad quality on mini purse seine boats, Rembang Regency, Central of Java

Mini purse seine boats in Rembang are divided into two sizes. The first one, namely mini purse seines measuring 10 - 20 Goss Tonnage (GT) (short trips) with a fishing operation duration of 3 - 7 days. The second one is mini purse seines measuring 21 - 30 GT (long trips) with a fishing operation duration of 7 - 10 days. The dominant catch on this boats is round scad, which used a cooling mechanism with ice blocks and bulking systems. This research evaluates the quality of round scad caught by mini purse seine boats (based on Indonesian National Standard/SNI 2729: 2013) and the quality of ice used in handling the fish (based on SNI 4872: 2015). The sampling technique was purposive sampling. Fish samples were carried out in the first and last hold on the short trips and long trips boats, where each handle of the fish was sampled in the upper, middle, and lower layers. Data analysis for sensory evaluation were analyzed by Kruskal Wallis statistics, while the TPC value of round scad was tested by ANOVA test. The laboratory test results obtained the sensory assessment of round scad. The value of the TPC round scad and the E. coli ice blocks are still within the limits of the Indonesian national standards, but the TPC scale of the ice block exceeds the standard limit of SNI. The Kruskal Wallis statistics results showed tha the difference in fish hold, the difference in the trip, and differences in fish hold layers had a significant effect on the sensory of scad. ANOVA test showed that differences in the fish hold and trip differences had a significant impact on the TPC of scad. In contrast, the difference in fish hold layers gave a non-significant effect on the TPC of round scad.Keywords:Quality organolepticTPcRound scadMini purse seineRembang

Minimasi Biaya Distribusi Es Balok Dan Es Kristal Menggunakan Metode Capacitated Vehicle Routing Problem Di Pt Agronesia Es Saripetojo Bandung

Companies can minimize distribution costs by determining the best distribution route from the company (depot) to customers spread across various locations. PT Agronesia Es Saripetojo Bandung Division has a problem determining the best distribution route because the distribution route changes every day depending on the customer's communication with the driver who asks to be served first. Thus the company cannot measure the performance of distribution costs and cannot evaluate the optimal number of vehicles to support distribution cost efficiency.
 This problem can be solved using the Capacitated Vehicle Routing Problem (CVRP) method which takes into account the number and capacity of vehicles, the demand for each replacement, and the distance from the depot to the customer so that a minimum total distribution cost is obtained.
 The results of the research provide a solution for the distribution of ice blocks and crystal ice using the Capacitated Vehicle Routing Problem (CVRP) method with the help of LOGWARE software, it has succeeded in determining the best route and at the same time minimizing distribution costs. Distribution cost efficiency can still be done by reducing 1 Mitsubishi Colt Diesel Engkel FE 71 vehicle, so there is an efficiency of = Rp. 267,000,-/day = 8.04%/day. Meanwhile, by reducing 1 Colt Diesel Engkel FE 71 vehicle, an efficiency of = Rp. 267,000,-/day = 7.92%/day. Meanwhile, vehicles that are not used can be rented or sold, thereby reducing the burden of fixed costs and variable costs.

Operasi penangkapan dan penanganan hasil tangkapan pole and line KM Sari Usaha 09

The utilization of marine biological resources in an effort to increase the production of fishery products has always received serious attention from fishing stakeholders. One of the fishing gear used in exploiting fish resources is pole and line. This study aims to examine pole and line fishing operations and methods of handling the catch on board. This factorrs are important in increasing production with maintained fish quality. This research is descriptive in nature and data collection includes primary data obtained directly from the source or research object, and secondary data obtained indirectly from the research object. Fishing operations include preparation activities, especially ship documents, fishing gear, food supplies, fuel and ice blocks. The operation of pole and line fishing gear uses live bait as a determining factor for fishing success. The types of fish caught are skipjack tuna, yellow fin tuna, dolphinfish, and rainbow runner. The steps taken in the process of handling caught fish on board include preparing catch handling equipment, handling freshly caught fish, and handling fish in holds.

New technologies of ice roads construction to maintain the sustainable cold chain of supply in the northern regions of Russia

The article reviews the current state of winter ice roads (winter glacial roads) and presents data that confirm the necessity of their service life extension in order to maintain the uninterrupted cold chain of supply in the northern regions of Russia. The regulatory documents that regulate the design engineering and construction of winter ice roads are analyzed. The existing methods and technologies of winter roads construction have been analyzed. The possibility of using the geosynthetic materials for ice roads reinforcement is considered, as well as possible challenges arising from their use are exposed for consideration. The use of chemical modifiers for the creation of structural materials based on water ice is shown to be prospective and promising, especially in combination with the reinforcement of ice blocks. Modern approaches to choice of ice modifying compounds and materials for ice reinforcing are described, as well as criteria achieved on the basis of their application. The scientific studies confirming the possibility of a significant increase in the bearing capacity of glacial coverage and, as a result, an earlier start of their operation is carried out. It is shown that the combined use of reinforcement and ice modifiers allowed the ice sample to maintain its integrity even under exposure to significant deformation loads. The technical possibility of additional reinforcement of ice transport routes as a result of optimizing the modal parameters of their formation, depending on weather conditions, is also described.

Treatment of an industrial wastewater for phosphorus and fluoride recovery by a process coupling block freeze concentration and precipitation

The work aims at developing a process for treating industrial wastewater from phosphoric acid and fertilizer production units by a coupled block freeze concentration-precipitation process. First, the block freeze concentration study, carried out on synthetic phosphoric acid solutions of concentrations ranging between 1.31 wt% 29.93 wt%, has shown that the purity of the ice block is strongly dependent on the initial concentration, the freeze duration, the thawing rate and the ice block temperature. Second, the block freeze concentration study, performed on a solution containing an orthophosphate-fluoride mixture, showed that the process increased the purity of the ice by the migration of occluded fluoride and orthophosphate ions until reaching a removal efficiency of F− and PO43− upper than 94 %. Further treatment by precipitation was studied on the first thawed fraction resulting from the freezing step. The results of the recovered liquid confirmed that, in the pH range between 2.4 and 12.73, the removal of fluoride and orthophosphate increased from 9.8 % to 96 % and from 6.3 % to 99 %, respectively. Precipitates characterization using methods such as X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy combined with energy dispersive X-ray analysis, indicated that CaF2, Ca5(PO4)3(OH)F and Ca5(PO4)3(OH) were successfully produced.

Ice breakloose friction.

We discuss the origin of the breakloose (or static) friction force when an ice block is slid on a hard randomly rough substrate surface. If the substrate has roughness with small enough amplitude (of order a 1nm or less), the breakloose force may be due to interfacial slip and is determined by the elastic energy per unit area, Uel/A0, stored at the interface after the block has been displaced a short distance from its original position. The theory assumes complete contact between the solids at the interface and that there is no elastic deformation energy at the interface in the original state before the application of the tangential force. The breakloose force depends on the surface roughness power spectrum of the substrate and is found to be in good agreement with experimental observations. We show that as the temperature decreases, there is a transition from interfacial sliding (mode II crack propagation, where the crack propagation energy GII = Uel/A0) to opening crack propagation (mode I crack propagation with GI the energy per unit area to break the ice-substrate bonds in the normal direction).

Design Analysis and Design of Coolbox Based on Thermoelectricity with Wind Power Plant Using 3D Modeling

Energy needs continue to increase from year to year in line with population growth in Indonesia. Therefore, wind turbines as a renewable alternative energy source to meet the energy needs of coastal communities. The use of heavy and high ice blocks has always been a problem for fishermen in fish catches, this has an impact on the quality of the fish caught. This thermoelectric coolbox with wind power plant is designed by combining the components of a thermoelectric coolbox and a wind turbine which functions to maintain the temperature in the coolbox so that the fish stored are more durable using electricity generated from the rotation of the wind turbine. This research uses the design and development (D&D) method and is supported by secondary data from published articles and news journals which aim to design a three-dimensional model of a thermoelectric coolbox using solidworks software. The results of the design analysis obtained turbine area, turbine height, chord length, torque value, shaft diameter and allowable shear stress. With the results of the analysis of the design of a thermoelectric coolbox with a wind turbine, it has the potential and benefits for the fishing profession and can be realized into a product.

Microbial Transport by a Descending Ice Melting Probe: Implications for Subglacial and Ocean World Exploration.

Ocean Worlds beneath thick ice covers in our solar system, as well as subglacial lakes on Earth, may harbor biological systems. In both cases, thick ice covers (>100 s of meters) present significant barriers to access. Melt probes are emerging as tools for reaching and sampling these realms due to their small logistical footprint, ability to transport payloads, and ease of cleaning in the field. On Earth, glaciers are immured with various abundances of microorganisms and debris. The potential for bioloads to accumulate around and be dragged by a probe during descent has not previously been investigated. Due to the pristine nature of these environments, minimizing and understanding the risk of forward contamination and considering the potential of melt probes to act as instrument-induced special regions are essential. In this study, we examined the effect that two engineering descent strategies for melt probes have on the dragging of bioloads. We also tested the ability of a field cleaning protocol to rid a common contaminant, Bacillus. These tests were conducted in a synthetic ice block immured with bioloads using the Ice Diver melt probe. Our data suggest minimal dragging of bioloads by melt probes, but conclude that modifications for further minimization and use in special regions should be made.