Number Of Shields Research Articles

Diverse volcanism and crustal recycling on early Mars

The relatively well-preserved ancient crust of Mars provides a natural window into early planetary evolution not available on Earth due to sustained tectonic recycling and erosion on this planet. Mars has generally been considered a one-plate basaltic planet, though recent evidence suggests magmatic evolution resulting in felsic crust might have occurred sporadically. Here we show multiple lines of evidence for diverse volcanism and complex volcanotectonics in the southern highlands of Mars within and around the ∼3.5–4-billion-year-old Eridania basin. Infrared remote sensing reveals bimodal volcanism consisting of olivine-bearing basalts and voluminous, widespread dacitic (64–69% SiO2, and possibly higher) volcanic deposits within a region of high crustal potassium. The diverse igneous compositions are associated with an extraordinary number and morphological range of volcanic structures, including domes, stratovolcanoes, calderas and pyroclastic shields occurring proximal to large (hundreds of kilometres in diametre) basins within the Eridania region. The 2–4 km-deep topographically concave-up basins have crustal thicknesses 10–20 km thinner than adjacent terrain and disrupt patterns of deeply seated remnant crustal magnetism. The Eridania basins may represent ancient episodes of crustal recycling via lithospheric delamination in which altered, hydrated volcanic materials were cycled downward and melted resulting in magmatic evolution analogous to pre-plate tectonic processes on the Archaean Earth.

Biometrics of neonates and characterization of the Amazon Turtle (Podocmenis expansa) nests in the Crixás-açu river, Mundo Novo, Goiás, Brazil

The objective of this study was to evaluate newborn biometrics and characterization of Podocnemis expansa turtle nests in the Crixás-Açu rivers, municipalities of Mundo Novo, Goais, Brazil. It consists of evaluating the newborns and the characterization of the nests after hatching. There was no statistical difference between eggs with oil, predatory nests, dead newborns, un hatched eggs, shell (total number of eggs counted within a nest), as well as hatching and survival rates for the distance of 30 meters from the river course. Animal weight, hoof length, hoof width, plastron length, plastron width or number of shields were obtained statistically significant considering the same fixed distance of 30 or greater than 30 meters from the river bank. In the eggshell analysis, there was a statistical difference regarding the amount of the element "Carbon" found, unlike the samples of pH, "phosphorus", "potassium", "hydrogen", "aluminium", "calcium", "magnesium" and matter. Organic. As for the particle size analysis of the sand extracted from the nests, there was a statistical difference in two sizes; 1 and 2 millimeters. This study shows that nests near vegetation are more successful in hatching.

HEATER OF THE HOLLOW CATHODE WITH LaB6 FOR OPERATION WITH HALL THRUSTERS

The article presents the results of design, development and laboratory tests at Space Electric Thruster Systems (Dnipro, Ukraine) of a hollow filament cathode based on lanthanum hexaboride (LaB6). The cathode is designed for joint operation with Hall thrusters of various input powers. The emitter material LaB6 is very promising, because has a high emissivity and low ionization potential. However, to realize all the advantages of considerate material, it is necessary to provide a sufficiently high operating temperature (1400 ° C). Therefore, when developing the filament cathode, special attention was focused on the development and research of one of the key elements of the filament cathode - the heater. Thermal calculations of the hollow cathode were carried out when it was heated with a heater, as well as when the cathode was operating in auto mode. The results of thermal calculations made it possible to identify the shortcomings of the cathode structure and parameters and determine the ways to eliminate them. Laboratory tests of a cathode with a different number of heater thermal shields have been carried out. The results obtained made it possible to provide the required operating temperature of the cathode emitter with a minimum number of heat shields. Laboratory tests of the cathode were carried out both in diode mode (to the external anode) and in conjunction with the ST-25 Hall thruster developed by the company. In the course of laboratory tests of the cathode, the power supplies for the discharge, the keeper, and the heater, which are components of the power processing unit of the Hall thruster, were used. In the frame of experimental studies, a cyclogram of the cathode starting process was obtained, which is necessary to form the Hall thruster starting sequence. The tests carried out confirmed the correctness of the selected technical solutions for the choice of the cathode and its heater. The developed cathode can be used both in low-power (up to 200 W) Hall thrusters and in thrusters with increased input power (up to 5 kW).

Effect of snow-covered ground albedo on the accuracy of air temperature measurements

Abstract. Solar radiation is one of the main factors which introduce significant deviations between thermometers reading and true air temperature value. Techniques to protect the sensors from direct radiative influence have been adopted almost since the beginning of meteorological observations. Reflected radiation from a snow-covered surface can also cause extra warming to thermometers hosted in solar shields, which are not always optimised to protect the sensors from this further radiative heat transfer. This phenomenon can cause errors in near-surface temperature measurements results, with a relevant impact on the quality of data records and series. This study experimentally evaluates the effect of reflected radiation from a snow-covered surface on the accuracy of air temperature measurements. The investigation is based on the evaluation of temperature differences between pairs of identical instruments, positioned above ground covered by natural vegetation, with one instrument in snow-free conditions and the other above a snow-covered surface, at the same time and at the same site. The work involved a representative number of sensors and shields, in terms of different typologies, technologies and engineering solutions, from different manufacturers. A mountain site with acceptable field conditions, offering long-lasting snow presence to maximise data availability, was selected to perform the experiment. Quantities of influence, such as relative humidity, wind speed and direction and solar radiation (global and reflected), were constantly measured. The main findings of this work show that none of the involved instruments were immune to the extra heating due to the snow-reflected radiation. Excluding nighttimes and days of high wind or low incident radiation, the differences among sensors positioned above natural soil and identical ones exposed to snow albedo ranged up to more than 3 ∘C. Solar screens with forced ventilation showed a partially reduced effect compared to most of the naturally ventilated ones. A full data analysis is reported here, together with complete results and uncertainties.

The taxonomic status of the vipers of the Pelias (kaznakovi) complex in the middle-flow of the Kura River basin in the East Transcaucasia

Recently, the Caucasian viper was found in a number of localities in South Ossetia (Tuniyev et al. 2017a,b; Tuniyev et al. 2019) and in the lower gate of the Borzhom Gorge of Eastern Georgia. Animals from the new localities are compared to Pelias kaznakovi from the Western Caucasus – northeastern Turkey and P. dinniki. The canonical discriminate analysis (CDA) showed that the snakes from the left-bank basin of the middle flow of the Kura River in East Georgia and South Ossetia differ significantly from Pelias kaznakovi from Krasnodar Territory and Abkhazia in the mean values of several plastic and meristic characters. Thus, there is discrimination of the groups allocated according to geographic location and gender. Cluster analysis based on meristic characters of pholidosis showed the distance between P. dinniki and the remaining “kaznakovi” complex forms. Based on the results of the analysis of the mitochondrial cytochrome b gene, the snakes from the left-bank basin of the middle flow of the Kura River form a separate cluster, not sister to Pelias kaznakovi. The results obtained on morphology, genetics and ecology of the studied vipers suggest the taxonomic validity of the vipers from the left bank basin of the middle flow of the Kura River in Eastern Georgia and South Ossetia. The species is named after Boris Tuniyev, who made a significant contribution to the study of the Caucasian herpetofauna and taxonomy of the shield-head viper snakes. Among the representatives of the “kaznakovi” complex, males of the new species are characterized by the minimal values of body length, pileus length, head width, number of ventral and subcaudal shields, as well as the shields around the eyes; differences are also noted in the structure of the hemipenis; the females have the minimum values of body length, pileus length, head width, number of shields around the eyes and loreals, fewer wings of zigzag. All known finds are located in the left bank basin of the middle flow of the Kura River from the Borzhom Gorge (east slope of Meskheti Ridge) in Georgia to the mid-altitude mountain districts of South Ossetia (east foothills of Likhsky Ridge and south spurs of Central Caucasus). Biotopes of the new species are character- ized by more xero-mesophilic traits and a moderately warm mezo-climate than the typical mesophilic biotopes of North-Colchian (Krasnodar Territory – Abkhazia) and, especially, Adzharo-Lazistanian (Georgia – Turkey) P. kaznakovi living in the humid subtropical climate.

Cost Analysis of a PTO Driveline Shielding Program: Are Effective Programs Cost-Effective?

This article describes a cost assessment of a PTO driveline shielding intervention. Considerations for effective occupational safety interventions beyond reductions in injuries or fatalities are described. The financial viability of combining various on-farm services to reduce intervention costs is discussed. PTO entanglements are a primary injury concern on U.S. farms, affecting adults and children. These events often lead to severe injury and permanent disability but can be prevented with proper use of PTO shielding. A promising strategy for increasing PTO shielding on farms has been the introduction of user-friendly shielding options by qualified safety specialists. This study looks at the cost-effectiveness of this approach. The cost-effectiveness of this PTO shielding strategy was calculated based on program-related costs, the PTO shield cost, the lifespan of PTO shields, and the number of PTO shields needed to prevent an entanglement. The cost per entanglement prevented was then calculated by dividing the total costs by the number of entanglements prevented in several cost-estimate scenarios. Costs were adjusted for inflation to 2019 dollars. Costs per entanglement prevented ranged from a low of $921,544 (assuming a 10-year PTO lifespan and using 12,487 as the number needed to treat, i.e., to prevent a PTO entanglement, referred to as the NNT) to a high of $18,583,492 (assuming a three-year PTO lifespan and 67,119 as the NNT). The cost per entanglement prevented at the median PTO lifespan of five years and median NNT of 39,802 was $6,612,244. Based on our estimates, the cost-efficacy of increasing PTO shielding using qualified safety specialists differs widely based on the shield lifespan and the number of shields needed to avoid one entanglement. However, if the cost of introducing PTO shields in on-farm visits is coupled with other on-farm services that defray these costs, then the cost-efficacy increases considerably.

The Greek shield as a metal artifact and its reflection in the story of the Croesus’ gifts in Thebes

The article is devoted to the study of archaeological evidences and literary tradition regarding ancient Greek shields as metal artifacts or as the artifacts made by the use of metal. Presented is an attempt at interpreting the names “σάκος” (sakos) and “ἀσπίς” (aspis), by which ancient authors called the Greek shields in the Archaic and Classical Periods. New data on the dating of some artefacts let assume that a number of shields, the production technology of which goes back to the Late Bronze Age or made later (in the Geometric or Archaic Periods) may have been displayed in sanctuaries under the influence of the artifacts from the Late Bronze Age. The authors propose a version according to which Herodotus, describing the Croesus’ gifts in Thebes, uses the word “σάκος”, thereby emphasizing the uncommonness of the golden shield, its heroic antiquity and the reliability of the Amphiaraus’ shield. Archaeological parallels and the words “φαενάν [ἀσπ]ίδα” from an inscription found in Thebes suggest that it was a round shield. Thisartifact had not only a religious, but also a historical and educational function, being an article that bounds up the Thebans with their heroic past. This work is supported by the Russian Science Foundation under grant No. 18-78-10001.

Investigation of effect of low emissivity shields on the thermal conductivity of low-density polystyrene

In this paper, we present an experimental study on the influence of low-emissivity aluminium shields on the thermal properties of low-density expanded polystyrene. As radiation is significantly influenced by the presence of shields only on low-density materials, experimental work has been done on low-density expanded polystyrene, of which the density was about 9,5 kg m−3. Expanded polystyrene panels have been measured by the Heat Flow Meter apparatus in our laboratory. Nine sets of measurements have been done. Every panel was cut horizontally, and aluminium foils were inserted between the slices as shields. As expected, the thermal conductivity decreased considerably with the number of slices in which the material was cut and the number of aluminium shields. We found a decrease in the thermal conductivity that can even reach 25 % if we cut the panel in 8 slices with 7 aluminium foils interposed between them. We compared the experimental results with our model, which considers the presence of shields in insulating materials, and this proposed model fits the experimental results with a good accuracy. This is because almost all experimental results are situated in a zone, which represents ±2 % of error.

Optimization of cryogenic architecture for LiteBIRD satellite using radiative cooling

Radiative cooling with thermal isolation shields can provide a reliable cooling system for instruments onboard satellites in orbit. We report the optimization study for the cryogenic architecture of the LiteBIRD satellite using radiative cooling. A trade study that changed the number of thermal shields and shield emissivity were conducted. The heat flow from 300 to 4.5 K, including active cooling by mechanical cryocoolers, was evaluated among the trade designs. We found that the design that consists of low-emissivity four-layer thermal shields is optimum in terms of thermal performance and system design. The optimum design achieved a heat load of 29.9 mW for the 4.5-K cooling stage, whereas the requirement was 30 mW with the assumed cryogenic system.

Electronic controlled CMOS inductor with patterned metal ground shields for fine inductance tuning application

This paper is on an inductance fine tuning technique which benefits from the idea of varying the number of metal plates of an inductor’s pattern ground shield (PGS) shorted to ground to change its magnetic fields. This technique is unique because the geometry and physical shape of the inductor remains untouched from its form in the process design kit (PDK) while the inductance is being tuned. The number of metal shields shorted to ground was controlled by an electronic circuit which consists of analog-to-digital converters and active switches. Both Sonnet EM simulator and Cadence Virtuoso were used for the inductor and circuit simulations. From the simulation, it was found that the inductance increased while the Q-factor decreased as more metal shields were shorted to ground. For instance, at 1.6 GHz, the simulated inductance was 8.8 nH when all metals were floated and 9.4 nH when all metals were shorted to ground. On the other hand, the simulated Q-factor was 10.4 when all metals were floated and 9.8 when all metals were shorted to ground. From both simulation and measured results, both inductance and inductance tuning range increased with frequency. From the measured results too, the inductance observed was 9.4 nH at 1.6 GHz, 10.8 nH at 2 GHz, and 13.5 nH at 2.5 GHz when all the metal shields were shorted to ground. The inductance tuning range was 6.2% at 1.6 GHz, 12.5% at 2 GHz, and 20% at 2.5 GHz. The measured results showed good correlation with the simulated results trend, but with smaller value of inductance, inductance tuning range and Q-factor.

Heat leakage of a vertical test cryostat for superconducting cavity based on variable arranged radiation shield

The vertical test cryostat, which is used to measure the cryogenic performance of a superconducting cavity is a liquid helium open vessel, and has high requirements for thermal insulation performance. The inner vessel of the cryostat is high-vacuum multilayer insulation, and the open side is multi-shield insulation. In order to further reduce the heat leakage through the cover plate of the cryostat at the open side, a variable arranged radiation shield spacing is proposed. The coupling heat transfer model was established for the cover plate, radiation shields, liquid surface and helium gas, and was verified by experiment. The influence of the radiation shields distribution on the heat leakage and the optimal radiation shield arrangement were obtained by numerical calculation. As the number of radiation shields is 11, the method of the variable arranged radiation shield, which is to arrange 7-layer radiation shields in the high temperature region and 4-layer radiation shields in the low temperature region, has a minimal heat leakage. The method can reduce the heat leakage by 4% compared with the equal spacing method.

Optimal placement of radiation shields in the displacer of a Stirling engine

The implementation of radiation shields in the displacer assembly of a Stirling engine is an effective way to reduce heat transfer losses. A FEA approach with ANSYS Workbench was utilized to determine the steady-state temperature profile throughout a displacer assembly, as well as the heat transfer from the hot end to the cold end of the displacer to optimize the position of the radiation shields. The results show that the surface finish is a critical aspect of reducing radiation losses since the higher emissivity cases resulted in higher displacer body temperatures and total heat flux to displacer body compared to the lower emissivity cases with the same number of shields and positioning. Even a single shield is capable of significantly reducing the radiation losses present in the displacer. The results also suggest it is more effective to place the shields uniformly along the entire length of the displacer cap. The results also demonstrated that there exits an optimal number of radiation shields that has the lease heat losses.

Figurines in the Road: A Protoattic Votive Deposit from the Athenian Agora Reexamined

In 1933, Dorothy Burr published a catalogue of a large Protoattic votive deposit located near the southwest corner of the Athenian Agora. Included within the deposit are a number of terracotta votive shields, horses, and chariots, as well as a remarkably well-preserved terracotta plaque depicting a “Mistress of Snakes.” There has long been a consensus among archaeologists that this votive assemblage is indicative of a cult of the dead. A reexamination of the deposit and its context suggests a rather different conclusion: the votives were dedications to Demeter, and came from the Eleusinion.

Morphometry of terrestrial shield volcanoes

Shield volcanoes are described as low-angle edifices built primarily by the accumulation of successive lava flows. This generic view of shield volcano morphology is based on a limited number of monogenetic shields from Iceland and Mexico, and a small set of large oceanic islands (Hawaii, Galápagos). Here, the morphometry of 158 monogenetic and polygenetic shield volcanoes is analyzed quantitatively from 90-meter resolution SRTM DEMs using the MORVOLC algorithm. An additional set of 24 lava-dominated ‘shield-like’ volcanoes, considered so far as stratovolcanoes, are documented for comparison. Results show that there is a large variation in shield size (volumes from 0.1 to >1000km3), profile shape (height/basal width (H/WB) ratios mostly from 0.01 to 0.1), flank slope gradients (average slopes mostly from 1° to 15°), elongation and summit truncation. Although there is no clear-cut morphometric difference between shield volcanoes and stratovolcanoes, an approximate threshold can be drawn at 12° average slope and 0.10 H/WB ratio. Principal component analysis of the obtained database enables to identify four key morphometric descriptors: size, steepness, plan shape and truncation. Hierarchical cluster analysis of these descriptors results in 12 end-member shield types, with intermediate cases defining a continuum of morphologies. The shield types can be linked in terms of growth stages and shape evolution, related to (1) magma composition and rheology, effusion rate and lava/pyroclast ratio, which will condition edifice steepness; (2) spatial distribution of vents, in turn related to the magmatic feeding system and the tectonic framework, which will control edifice plan shape; and (3) caldera formation, which will condition edifice truncation.

A Comparison of Interventional Approaches for Increasing Power Take-off Shielding on New York Farms

ABSTRACT Objective: Power take-off (PTO) driveline entanglements are a primary source of injury on US farms. As with many farm injury concerns, hazard control technology is widely available for mitigating the risk of these entanglements. Despite the availability of hazard control technology, PTO shields are damaged or missing on approximately 57% of PTO driveline implements in New York. Given the catastrophic nature of entanglements and the ready access to safety technology, a better understanding of what motivates farmers to install or replace PTO shields is warranted. Methods: To examine this question, agricultural health and safety researchers in New York State conducted an initial comparison of PTO shield sales on farms receiving one of three different interventional approaches. These included PTO shield audits, a social marketing campaign, and on-farm safety services. PTO shield purchases were tracked from January 2011 through June 2016 on farms receiving these interventions and on other farms that were not exposed to interventional strategies. Results: Results indicate that a significantly higher number of PTO shields were purchased on farms that requested and received on-farm safety services versus farms that were exposed to PTO shield audits, the social marketing campaign, or the control group. PTO shield sales were slightly elevated on farms receiving driveline audits, as compared with control farms (although these differences were not significant). Conclusions: No marked differences in sales were noted between control farms and farms exposed to the social marketing campaign. Only one of the three interventional strategies (on-farm safety services) approached the number of PTO shield sales necessary to prevent an entanglement.

A Study for Design Factors of RTG to Increase Thermal Insulation Efficiency

RTG (Radioisotope Thermoelectric Generator) is a power generation system producing electricity by converting the thermal energy gained from shielding radioisotope. RTG generates power without being charged from outside and as it utilizes radioisotope, RTG mainly serves as an energy source operated for a specific purpose in environment hardly accessible by human. Its design structures vary according to its purpose of operation, thermal source of operation and environment of operation. Since RTG is a power generation system, it should have the highest power efficiency with limited heat source. In this study, heat transfer analysis was implemented to investigate diverse design factors influencing the insulation system of RTG for aerospace use. Design factors considered in this study were silver coating, number of radiation shields inside vacuum insulation and supporter material. As a result, it was found that, depending upon design factors, insulation efficiency increased by 9.3% and finally insulation efficiency of RTG v2.0 was estimated at 84.3%.

Morphological variation of Philodryas patagoniensis (Girard, 1858) (Serpentes, Dipsadidae) from Brazil, based on the study of pholidosis, coloration and morphometric features

Abstract The current study aimed to verify the relationship between the patterns of coloration, the morphometrical features and pholidosis of specimens of Philodryas patagoniensis from Brazil, with the sexual dimorphism of this species. We studied specimens of P. patagoniensis deposited in several herpetological collections from Brazil. A total of 355 specimens were analyzed, of these 145 were males (87 adults and 58 juveniles) and 210 were females (134 adults and 76 juveniles). Adult specimens exhibit sexual dimorphism in snout-vent length, tail length, head length, number of ventral shields, and number of subcaudal shields. The analysis of variance showed that the adult females are significantly longer than adult males, both at snout-vent length and tail length. Females have a greater number of ventral shields (138-210) than males (151-200). The specimens studied also exhibit two distinct patterns of coloration unrelated to geographical or sexual variations.

The Influence of Communication About Safety Measures on Risk-Taking Behavior

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 179255, “The Influence of Communicating About Safety Measures on Risk- Taking Behavior,” by Jop Groeneweg, SPE, and Emma ter Mors, Leiden University, prepared for the 2016 SPE International Conference and Exhibition on Health, Safety, Security, Environment, and Social Responsibility, Stavanger, 11–13 April. The paper has not been peer reviewed. Risk-taking behavior is an important contributing human factor to incidents and is notoriously difficult to influence. Anecdotal evidence suggests that people have a hard-wired optimal perceived risk level. People compensate for risk-reducing measures by behaving in a riskier fashion until the desired level of risk is reached again. This study looked at the effect of the number of shields of protection and uncertainty on the risk-taking behavior of the participants. Introduction The main aim of safety research is to identify ways to prevent accidents and to ensure the safety of workers. Human error—or, in other words, unsafe behavior—has been found to be a major cause of accidents, and its elimination, therefore, is a prime goal for improving safety. The human factor is most effectively addressed by tackling the organizational system instead of focusing on incorrect actions by individuals. An effective strategy is to increase the level of protection or the number of safety barriers. The concept of the safety barrier features most prominently in the Swiss-cheese metaphor of accident causation. The Swiss-cheese model describes accidents as being caused by unchecked hazards that are allowed to cause losses. A series of barriers is placed between the hazard and that which may be harmed. The barriers keep the hazard under control and prevent it from causing harm. However, these barriers are always less than 100% adequate and contain weaknesses or holes. The barriers, therefore, often are compared to slices of Swiss cheese. Unlike real Swiss cheese, the holes in the barriers are dynamic and open and close at random. When these holes in the barriers are aligned, a path is created, leading to a potential accident. Intuitively, one would assume that safety improves proportionally both to the protection measures taken and to the improvements in the design of such measures. The more protective equipment given to the workers, the safer they will be, either because of a reduced risk of accident or because such measures mitigate the effects of accidents. This approach assumes that human error can arise from unintended actions such as memory lapses and attention failures. However, it can also be attributed partly to intended actions such as risk taking. The question addressed in this paper is related to the extent to which people’s risk-taking behavior was influenced by their awareness of the numerous preventive interventions in place. The pivotal issue that arises is whether people adapted their risk-taking behavior as a result of their awareness of the number, and of the effectiveness, of the barriers in place.

Overview of Architectures with Arduino Boards as Building Blocks for Data Acquisition and Control Systems

Standard SBCs (Single Board Computer) with number of standard shields and sensors can be used as building blocks for rapid development of network of intelligent devices with sensing, control and Internet access. Arduino family of boards having high popularity and large number of sold units featuring open access, reliability, robustness, standard connections and low prices, possesses large potential for implementation of autonomous remote measurement and control systems of various levels of complexity. As Arduino boards can function independently, they are complete small computer platforms that can perform various tasks requiring some kind of interaction with the outer world. Arduino boards can be used and programmed in various ways, and can be arranged in various combinations forming some typical implementation architectures that this paper discusses. Starting from basic and simple configurations, more advanced are gradually considered from the aspects of chosen way of programming and combining with other boards. Special attention is devoted to NodeJS as programming platform for Arduino boards and considerations of libraries used with Arduino boards like Johnny-Five, Galileo-io firmata equivalent, mraa library and other ways of program access to GPIO like Linux Sysfs. As typical representatives of Arduino boards’ family, the Arduino Uno, Arduino Due and Arduino Galileo were selected, with justification that all other not mentioned boards are somewhere between those selected, according to official hardware specifications.

Optimum design of liquid helium dewar with vapour cooled shields

The work presented aims to develop a numerical model which can be used to design a vapour shielded liquid helium (LHe) Dewar without LN2 Shield. This model can compute the position of shields and the Net Evaporation Rate (NER) based on the capacity and number of vapour cooled shields (VCS) given by the user. The effect of neck dimensions on the heat in-leak is also given by this model. Heat in-leak design calculations are done using Finite Difference Method (FDM). A computer program is developed using MATLAB®. The results can be obtained either in graphical form or in terms of minimum NER and optimal positions of the VCS. The modelis validated against available results in literature and additional results are discussed in detail. This program can be extended to estimate the neck dimensions and position of shields for any given capacity, number of shields and allowable boil-off rate.