Bell Size Research Articles

Evaluation of microplastic pollution and risk assessment in a tropical monsoonal estuary, with special emphasis on contamination in jellyfish

Estuaries, which serve as vital links between land and coastal ecosystems, play a significant part in facilitating the transfer of plastic waste from the land to the ocean. In this research, we examined the prevalence, characteristics, and ecological risks of microplastics (MPs) in the extensively urbanized Cochin Estuarine System (CES), India. Additionally, it represents one of the initial evidence-based examinations of MPs ingestion by jellyfish in Indian waters, focusing on Acromitus flagellatus, Blackfordia virginica, and Pleurobrachia pileus species. The abundance of MPs found in the surface water of the Cochin Estuarine System (CES) varied between 14.44 ± 9 to 30 ± 15.94 MP/m3, with an average of 21.6 ± 11 MP/m3. In both surface waters and jellyfish from the Cochin Estuarine System (CES), fibers were the most prevalent type of MPs, with polyethylene (PE), polypropylene (PP), and polyamide (PA) being the most common polymer varieties. To evaluate the current levels of MPs and their effect on the CES, the Pollution Load Index (PLI), Potential Ecological Risk Index (PERI), and Polymeric Risk Index (H) were utilized. The high PLIestuary values (20.33), high Hestuary values (234.02), and extreme PERIestuary value (1646.06) indicate that the CES is facing an extreme ecological risk. Among the 280 jellyfish individuals examined, 118 (42.14%) were recognized to contain MPs with an average of 1.54 ± 2.68 MPs/individual. Pearson bivariate analysis revealed a significant correlation between the jellyfish bell size and number of plastics per individual. Comparison between jellyfish species revealed, the majority (66%) of the MPs identified in jellyfish were from A. flagellatus and 44 among the 50 jellyfish examined (88%) had MPs. These findings suggest that A. flagellatus may be a potential sink for MPs and may be utilized to be a bioindicator for monitoring MPs contamination in estuarine systems, aiding in future plastic pollution mitigation efforts.

A practical hybrid approach to the problem of surveying a working historical bell considering innovative measurement methods

The article proposes using a novel hybrid measurement method, with expected precision results, to determine the characteristic of the historic, 17th-century bell. In an interdisciplinary approach, modern and non-invasive physical and chemical measurement methods were used. Based on the monitoring (measurements and laser scanning), a three-dimensional geometric model was built to calculate the bell size and analyze its condition depending on material consumption. Next, chemical measures of the bell samples were carried out to determine the material properties. For that purpose, advanced precision microscopic techniques were used. Based on the geometric model and chemical studies, the material properties and density of the bronze were determined using additive assumptions. Measurement accuracy and data quality were evaluated statistically. The method allows reliably determining the bell's weight without needing to dismantle it or external intervention. The approach is helpful for practitioners performing conservation work on such objects.

Histological Investigation of the Female Gonads of Chiropsalmus quadrumanus (Cubozoa: Cnidaria) Suggests Iteroparous Reproduction

The box jellyfish Chiropsalmus quadrumanus (Chirodropida: Cubozoa: Cnidaria) is common in warm waters. Although it is assumed that external fertilization is a characteristic of Chirodropida, the life history of C. quadrumanus is not yet known since its reproductive behavior has never been described, nor has the polyp has been found in nature. As a result, in the absence of documentation of reproductive behavior, we sought to test the hypothesis of external fertilization through a histological analysis of the female gonads. Herein, we analyze ten females collected in São Paulo and Rio de Janeiro (Brazil) and describe the gonadal organization and pattern of oocyte development. The discovery of four distinct stages of oocyte differentiation augments the scant existing reports of the structural and functional maturation of sex cells in Cubozoa species. Furthermore, the gonads of mature females comprise both mature (average diameter of 122 µm) and immature oocytes, suggesting that C. quadrumanus is iteroparous and exhibits multiple reproductive cycles during its life. Medusa bell size was not found to correlate with maturity state as even small females possessed a high percentage of oocytes in late vitellogenesis, suggesting that sexual maturation occurs rapidly in C. quadrumanus females.

Assessing Magnesium Chloride as a Chemical for Immobilization of a Symbiotic Jellyfish (Cassiopea sp.)

Immobilization of marine invertebrates for research purposes has been commonly used and is often necessary to obtain high-quality findings. Despite these approaches being standard procedures, they can affect the specimens, and their responses as well. The effectiveness of magnesium chloride (MgCl2) to “narcotize” marine invertebrates has been recognized since 1946. Here, we determine the concentration of MgCl2 that immobilizes Cassiopea sp., at jellyfish stage, effectively and quickly, without causing mortality. The specimens were exposed to different concentrations of MgCl2, until the range was narrowed, and the most effective concentration was found (0.092M). In the final experiment, the jellyfish (~ 8.68 cm ± 1.70 SD of diameter) were exposed to a 0.092M MgCl2 solution for 2 and 24 hours. Before, during, and after the exposure we monitored the following biological responses: (1) cessation of bell pulsations, (2) responsiveness to bell-tap stimulus, (3) photochemical efficiency, (4) bell pulsation, (5) recovery time, and (6) survival after 24 and 48 hours from exposure. Environmental conditions (pH and dissolved oxygen, dO2) were monitored as well. Our findings indicate that, despite being an effective concentration for immobilization of Cassiopea sp. at jellyfish stage, their bell pulsations were significantly affected both after 2 and 24 hours when comparing the values measured in the “pre-incubation” and “immediate post-incubation” phases, whereas bell size was significantly affected only in the 24 hours incubation. In conclusion, we suggest that this concentration can be used to immobilize Cassiopea sp.at jellyfish stage for short-term analyses. However, the limitations related to the use of this chemical should be reported, as it could lead scientists to misleading conclusions.

Impacts of Light and Food Availability on Early Development of Cassiopea Medusae

The Cassiopea genus is an emergent focus for behavioral, ecological, and genetic research. Cassiopea ephyrae, a key intermediate in the life cycle of this benthic jellyfish, have been left out of much work on the genus. Here we investigate the Cassiopea xamachana ephyra response to six combinations of light and feeding regimes. We show that zero light condition results in fast bleaching of ephyrae and significant reductions in bell size and predation success. We also show that ephyrae starved in sub-compensation level light experienced only meager reductions in size over 42 days, and those starved in zero light were still largely recoverable at 28 days. Developmental trajectories on various metrics of Cassiopea xamachana ephyrae were significantly impacted by both light and feeding level in the first 42 days of life.

Effect of bell size on sound characteristics of cymbals

Effect of bell size on sound characteristics of cymbals

The Study of the Distribution and Deformation of Burden Layer in 250 Ton/Day Mini Blast Furnace Using Discrete Element Method

Based on the abundant nickel ore resources in Indonesia, it is necessary to develop nickel ore processing technology. One of the commercially proven nickel processing technology is Mini Blast Furnace (MBF). The feeding process in MBF using charging system. So, the burden material distribution in MBF can be controlled. The burden material controlling is important process in MBF. The distribution of burden material will affect the gas flow in MBF. This research focuses to study the effect of large bell diameter size to burden materials distribution in MBF using Discrete Element Method. After analysis, the differences of large bell diameter size will affect the burden materials distribution. If the diameter of large bell is greater, the impact point during charging process will be closer to the wall area. Then, the impact area on the surface of the layer will be on top of the layer. The distribution of burden materials in MBF is influenced by large bell size, kinetic energy at impact, particle mass, and particle size and layer stability. For particles distribution, the particles with small density (coal and dolomite) tend to be concentrated in the center zone. On the other hand, the particles with large density (ore) tend to be concentrated in the intermediate and peripheral zone. For the MBF start-up process, the best gas flow can be achieved by using large bell and MBF inner diameter ratio of 7: 10.

CFD-based design and analysis of air-bearing-supported paint spray spindle

In this paper, an analytical scientific approach is presented for the design and analysis of an air-turbine-driven paint spray spindle, and it is used to improve further the design concept of the existing spindle applied in automotive coating and paint spraying applications. The current spindle on the market can operate at a maximum speed of 100,000 rpm and features a maximum bell size of 70 mm diameter. Given the increasing demands for high automotive coating/painting quality and productivity in assembly, the design and development of a paint spray spindle with a speed of 145,000 rpm or higher is needed. Computational fluid dynamics (CFD)-based simulation is applied in the approach. Accordingly, CFD simulation-based design and analysis are undertaken, covering the characteristic factors of velocity, pressure of the air supply, rotational speed of the air-turbine, and torque and force reaction on the turbine blades. Furthermore, the turbine blade geometric shape is investigated through the simulations. Three geometrical concepts have been investigated against the original model. The results on Concept_03 verified the higher angular velocity speeds against the theoretical model. The pressure and velocity effects in the blades have been investigated. The results show that the pressure and velocity of the air supply driving the turbine are critical factors influencing the stability of turbine spinning. The results also demonstrate that the force acting on the blades is at the highest level when the adjacent face changes from a straight surface into a curve. Finally, changing the geometrical shape in the turbine likely increases the tangential air pressure at the blades surface and relatively increases the magnitude of the lateral torque and force in the spindle. Notwithstanding this condition, the analytical values surpass the theoretical target values.

Re-description of Chrysaora pacifica (Goette, 1886) (Cnidaria, Scyphozoa) from Korean Coastal Waters: Morphology and Molecular Comparisons

The nomenclature of the sea nettle jellyfish from Korea was initially described as Dactylometra quinquecirrha Agassiz, 1862. However its identity has been questioned on the basis of its local distribution and molecular data. Here, we examined morphology and DNA sequences of nuclear rDNA using specimens collected from southern Korean waters in August 2014. Based on morphological characteristics (bell size, umbrella pattern, number of tentacles and lappets) and distribution locality, we reassign the Korean D. quinquecirrha to Chrysaora pacifica (Goette, 1886), and provide a re-description accordingly. The molecular identity of C. pacifica was further confirmed by comparison of nuclear ribosomal DNA sequences.

Distribution of Nemopilema nomurai in the southwestern Sea of Japan related to meandering of the Tsushima Warm Current

We investigated the horizontal distribution of Nemopilema nomurai medusae using a midwater trawl in the southwestern Sea of Japan from September to October of each year from 2006 to 2012. Numerous medusae of this species found in 2006, 2007, and 2009 were mainly distributed far (>40 km) from the mainland of Japan in the western part of the survey area, but were distributed in the stations closest (<25 km) to the mainland in the eastern part, particularly in 2006 and 2009. These distribution patterns were associated with the path of the second branch of the Tsushima Warm Current (TWC) that flows offshore to the west of Oki Islands and usually approaches the mainland of Japan to the east of Oki Islands. Differences in jellyfish distribution across the survey periods were related to the distribution of the second branch being associated with types, position and intensity of eddies in the eastern part of the survey area. Hence, the formations of eddies and consequent variation in the path of the TWC would be responsible for transporting medusae from offshore to near the mainland to the east of Oki Islands. Individuals with large bells accumulated in the northwestern part of the survey area, where a cyclonic eddy was present downstream of the third branch of the TWC. This variation in bell size distribution may be ascribed to differences in the physical and/or biological factors among the three branches of the TWC.

The utility of statoliths and bell size to elucidate age and condition of a scyphomedusa (Cassiopea sp.)

Scyphomedusae play important roles in marine ecosystems and are of economic significance. However, no reliable techniques for estimating scyphomedusa age have been documented. This study focused on the utility of Cassiopea sp. (Cnidaria: Scyphozoa) statoliths, statocysts, and body size as proxies for age of medusae. Reared medusae of known age and a manipulative experiment were used to assess the accuracy and reliability of four measures of age: number of statoliths, size (diameter) of statoliths, area of statocyst (housing statoliths), and bell diameter. Bell diameter provided the most accurate measure of age under constant conditions, but was increasingly inaccurate under varying environmental conditions. In contrast, the average number of statoliths per medusa reflected age with relatively low accuracy, but did not vary with changes in food availability and salinity. Only temperature influenced the average number of statoliths. Comparisons of bell diameter to the number of statoliths in medusae under low food availability to those fed well showed that the ratio of medusa size to the number of statoliths can be used to recognise medusae that are relatively poorly conditioned. Statoliths, therefore, provide a tool for studying both population ecology and the influence of environmental variation on medusa growth.

Design characterization and testing of a custom air horn

Construction and testing of an air horn can provide educational insight into how certain design decisions can influence resulting acoustic properties. Using readily available materials such as pvc pipe and tin sheeting, one can construct an air horn capable of producing sound waves in the 100+ decibel range and frequencies between 150 and 400 Hz. Upon completion of a prototype, many experimental opportunities are available. The degradation of sound intensity over a distance can be tested by use of a sound level meter. Due to the unidirectional behavior of the sound waves from the horn, samples from different distances and angles from the source can provide more understanding of how sound propagates as a wave in an open environment, as opposed to it being a simple directional wave. Upon completion of the testing, changes to the initial construction design can be implemented to investigate the relationship between the new model’s performance and the prototype’s. The air horn provides many opportunities for experimentation and testing. For example, frequencies and sound intensity can be altered by making design adjustments such as: diaphragm size, diaphragm material, housing material, bell size, nozzle length, etc. With a better understanding of the inner workings of these sound sources, one could use this design as a blueprint to expand the concept to either much larger or much lower frequency ranges which have applications in many different fields of study.

Measurement of swimming speed of giant jellyfish Nemopilema nomurai using acoustics and visualization analysis

A species of giant jellyfish, Nemopilema nomurai, which has appeared only recently in the East China Sea, is an emerging nuisance in the northeastern region of Asia because of its extensive damage to fisheries. Until now, the biomass estimates of these jellyfish have mainly been obtained using trawl sampling and sighting survey methods. However, it is also necessary to determine the origin and diurnal migration patterns of these jellyfish. Drawbacks of the trawl sampling method are that it is effective only in estimating the density of jellyfish population distributed throughout the entire water column and requires considerable time. Another common analysis technique is the sighting method, which is effective only in the estimation of he density of jellyfish distributed in surface areas. The sighting method can determine distributions over wide areas in a short time. This method has limitations in investigating the vertical distribution and swimming behavior of jellyfishes. In our study, we utilized an echo sounding method extensively and effectively to overcome these limitations. Our method involved the use of a scientific echo sounder, acoustic camera, and conductivity-temperature-depth instrument during the drifting of a research vessel at various stations in the Yellow Sea. The acoustical method of particle tracking velocimetry (PTV) was used to analyze the swimming speed according to the vertical distribution of N. nomurai jellyfish. Results of the scientific echo sounder indicated that the jellyfish were mainly present in the water column from the surface up to a depth of 40 m. The mean swimming speed of the jellyfish was estimated as being 0.6 times the bell size (BS), with a tendency to maintain a certain speed. Further, results of a Monte Carlo simulation showed that the swimming speed was in the range of 0.46–0.89 BS. These results might be used as an index in a migration model, which may be useful to forecast the behavior and origin of the giant jellyfish entering inshore areas on a massive scale in northeastern Asia.

Clarifying the identity of the Japanese Habu-kurage, Chironex yamaguchii, sp. nov. (Cnidaria: Cubozoa: Chirodropida)

Here we describe the new species Chironex yamaguchii (Cnidaria: Cubozoa) from the Ryukyu Archipelago, Japan. This highly venomous cubomedusa, commonly referred to as Habu-kurage in Japan, is the culprit for several fatalities in Japanese waters. The scientific name adopted for this species in the literature is Chiropsalmus quadrigatus, but our taxonomic investigations show that this represents a case of mistaken identity. In fact, Habu-kurage is a close relative of Chironex fleckeri, which is particularly interesting because the latter has a reputation for being the most venomous animal known. Differences in the shape of the pedalial canal bend, the number of tentacles, and bell size distinguish the two species. In addition to Japan, Chironex yamaguchii is widely distributed in the Philippines.

Changing form and function during development in rowing hydromedusae

Bell morphology, propulsion and foraging appear to be interdependent traits among medusan lineages. In general, taxa that possess large oblate bells swim via rowing propulsion and forage as cruising predators, and taxa with small prolate bells swim via jet propulsion and forage as ambush predators. However, hydromedusae from the taxa Leptothecata (referred to here as lepto- medusae) experience large changes in bell size and shape during their development. We used video analysis to evaluate changes in bell morphology and kinematics, fluid interactions and behavior of 2 leptomedusan species, Aequorea victoria and Eutonina indicans, during these developmental transi- tions. Both species begin as small, prolate, jetting juveniles ( 0.5 cm diameter). In addition to morphological and propulsive alterations, we observed changes in behavior, whereby as jetters they rarely swam and as rowers they swam nearly continuously. These findings demonstrate that bell fineness, velar aperture ratio and bell kinematics interact to determine fluid interactions and thus determine propulsive mode.

Finite element studies of hand bell modes.

Hand bell modes are identified by indices m and n (m, n), where m refers to the number of nodal lines crossing the crown and n refers to the number of circumferential nodal lines. For high m values, depending on the bell size, no n = 0 modes exist. For such large m modes, the n = 1 nodal line is located very close to the mouth of the bell, rather than near the middle of the bell as is the case for (m,1) modes, where for the same value of m, an n = 0 mode exists. These modes are generally labeled as (m, 1*) modes. Finite element studies of mode sections of increasing complexity indicate that only when two curvatures are introduced, conditions are adequate to give rise to (m, 1*) modes. Computer generated images and animations of mode patterns corresponding to increasingly complex geometries will be illustrated.

Abundance, growth and food demand of the scyphomedusa Aurelia aurita in the western Wadden Sea

Medusae of Aurelia aurita are found in the western Wadden Sea from the beginning of May till August with maximum numbers of 250 to 500 individuals per 10 3 m 3 during May-June. The existence of a continuous ebb surplus suggests an origin from polyps living in the inner parts of the estuary and a transport or migration of the released medusae towards the North Sea. Growth is fast; a bell size of 20 cm diameter is reached within 3 to 4 months. The species is important as a predator from May to July, reaching maximum carbon biomass values of 12 to 18 g C·10 3 m −3. Predation by A. aurita may affect the recruitment of one of its food sources, viz. fish larvae.

Studies on character Association and rain analysis in F₂ Generation of some G. arboreum (L.). Crosses

Correlation and path analysis were studiad in F2 generation of 21 crosses of G. arboreum. Seed cotten yield was positively and significantly associated with plant height sympoola per plant, bolt number and harvest index. Ginning percentage and halolength showed positive association with number of seeds per ball. Path analysis revealed plant height, bell size, number of seeds per boll and harvest index as highest direct contributors to yield while boll number and sympedia per plant Indirectly contri- buted to yield Halolength via boll number, bell size and sympodia per plant and ginning percentage vin seeds per boll, sead index, liat index and harvest index affected the seed cotton yield.