Number Of Scallops Research Articles

The Cultivation of Scallop (Patinopecten yessoensis) in Hokkaido, Japan

Scallop culture is a widely practiced aquaculture activity in Japanese waters that involves collecting wild scallop spat and then growing the spat to a marketable size. This study aims to determine how the cultivation system, technology, and transportation are applied in scallop aquaculture in Japan. This research was conducted from December 2022 to June 2023 at a family scallop farming business in Ishikari, Hokkaido, Japan, hereafter referred to as Company X. This research utilizes a descriptive method with literature exploration and direct observation methods with a case study at Company X.Based on the literature study and activities at Company X, the cultivation media used and transportation are important parts of the scallop culture activities. The cultivation media used at Company X include onion mesh bags, Pearl nets, and lantern nets. The current transportation technology of scallops is carried out in two areas, namely sea, and land, using the open dry system transportation method, exposure method, and oxygen method. Marine transportation uses Hydraulic Cranes for Shipboard Use (Marine Cranes) technology applied to two specialized vessels of 9.7 and 12 GT with truck-mounted crane classification. Land transportation for the delivery of young scallops uses plastic container baskets covered with wet rice sacks to prevent dryness and the scallops inside the baskets from biting each other. After that, the scallops are transported by freezer truck, while land transportation for shipping adult scallops uses a freezer truck filled with oxygenated seawater. The size of the wind blowing at sea, the time of pickup - delivery, and the number of scallops needed are important factors in transportation activities.

Geographic Information Systems (GIS) as a Tool for Positive Identification from Frontal Sinus Radiographs

Frontal sinus radiographs are frequently used to identify human remains. However, the method of visually comparing antemortem (AM) to postmortem (PM) cranial radiographs has been criticized for being a subjective approach that relies on practitioner experience, training, and judgment rather than on objective, quantifiable procedures with published error rates. The objective of this study was to explore the use of ArcMap and its spatial analysis tool, Similarity Search, as a quantifiable, reliable, and reproducible method for identifying frontal sinus matches from cranial radiographs. Using cranial radiographs of 100 individuals from the William M. Bass DonatedSkeletal Collection, the frontal sinuses were digitized to create two-dimensional polygons. Similarity Search was evaluated on its ability to identify the correct AM radiograph using three variables: the number of scallops and the area and perimeter values of the polygons. Using all three variables, Similarity Search correctly identified the true match AM polygon in 58% of the male groups and in 62% of the female groups. These results indicate that ArcMap can be used with frontal sinus radiographs. However, further analysis of the three variables revealed that scallop number did not provide sufficient information about frontal sinus shape to increase the accuracy of Similarity Search, and area and perimeter only captured the size of the frontal sinus polygons, not shape. This research is a first step in developing a user-friendly, quantifiable frontal sinus comparison method for the purpose of positive identification.

Computational analysis for scallop seals with sickle grooves, part I: Leakage performance

Reducing of leakage rate of annular seals is an important objective of sealing technology. A number of noncontact seals are used for hermetic sealing of centrifugal compressors shafts such as: annular, labyrinth, honeycomb, hole pattern, pocket and scallop seals. In the art, scallop seals are of great interest in terms of reducing costs and time of manufacture. This paper presents results of calculation of leakage rate characteristics of scallop seals with sickle grooves (SSSG) depending on seal geometry. The Computational Fluid Dynamics (CFD) technique is used for calculation of hydrodynamic characteristics of seal. The Design of Experiment (DOE) technique is used for analysis of influence of scallop depth and width, rib width and number of scallops in circumferential direction on sealing performance of scallop seal. Such a comprehensive approach to the calculation using computational methods allows improving and further optimizing the existing designs of scallop seals.

Influence of scalloping on electrostatic forces in comb drive microdevices

Deep reactive-ion etching process is one of the most widely used manufacturing processes for micro-electro-mechanical-system (MEMS) devices, but the main problem with this process is that it leads to undesirable fabrication defects such as slanting, scalloping, etc. In this work, we develop analytical model to capture the effect of scalloping on electrostatic forces in a MEMS-based comb structure. In addition, we also modify the formula to include the parameters related to the size as well as number of scallops. To develop the model, we assume the shape of a scallop as elliptical which is characterized by major axis (2a) and semi-minor axis (b). To validate the model, we compare results with finite element results obtained using Coventerware for single as well as multi-scallops. Subsequently, we discuss the combined effect of scalloping and slanting on electrostatic forces in a comb drive structure. The model presented in the paper may be useful at the design stage of various comb drive MEMS devices such as MEMS gyroscopes.

Interactions between predatory sea stars ( Asterias amurensis and Distolasterias nipon ) and Japanese scallops ( Mizuhopecten yessoensis ) and implications for scallop seeding in mariculture

Sea stars are a key group of species in benthic marine ecosystems and represent the primary cause of mortality for cultured scallops. In the mariculture grounds of Japanese scallops (Mizuhopecten yessoensis) in north-eastern Japan, two sea star species, Asterias amurensis (AA) and Distolasterias nipon (DN), are serious predators. However, the predatory impact of these sea stars on scallops remains unquantified, with limited information being available on the biological characteristics of DN. We compared the predatory impact of both sea star species by evaluating their predatory behaviour (i.e. probability of predation and number of captured scallops) on scallops in laboratory experiments. Both sea star species preferred smaller scallops over large ones, with the probability of predation and the number of scallops being preyed on increasing with increasing water temperature. However, DN had a greater predation impact than AA. For instance, the probability of predation by DN was higher, with more scallops being consumed. In particular, compared to AA, DN continuously captured small scallops and fed on larger scallops. Furthermore, the predatory impact of both sea star species (particularly DN) on small scallops peaked at high temperatures. In conclusion, our results present information that could help improve the survival rate of seeded scallops in mariculture systems.

Predation of Sea Scallops and Other Indigenous Bivalves by Invasive Green Crab,Carcinus maenas, from Newfoundland, Canada

ABSTRACT Populations of green crab (Carcinus maenas) have expanded within Newfoundland, and this has raised concern from fish harvesters and scientists regarding bivalve predation in coastal areas on species such as juvenile sea scallops (Placopecten magellanicus). We used 2 microcosm experiments to determine (1) the effects of water temperature (5°C and 12°C) on scallop predation; (2) scallop size selection in small and large green crabs and a large indigenous predator, the rock crab (Cancer irroratus); and (3) bivalve prey selection in large green crabs between softshell clams (Mya arenaria), blue mussels (Mytilus edulis), and sea scallops. Overall, green and rock crabs captured 4 times more scallops in warm water (12°C) than cold (5°C). Large green (60–70 mm) and rock (75–90 mm) crabs captured similar numbers of scallops, selected medium-size (30–40 mm) scallops, and avoided small (10–20 mm) scallops. Small green crabs (40–50 mm) captured only small scallops. Large green crabs selected softshell clams ...

Fundamental studies of bloodstain formation and characteristics

A detailed understanding of blood droplet impact dynamics and stain formation is an essential prerequisite to the interpretation of both individual bloodstains and spatter patterns. The current literature on theoretical models for the spreading and splashing of liquid drops on surfaces relevant to the forensic context of bloodstain formation has been reviewed. These models have been evaluated for a paper substrate using experimental data obtained as function of droplet size, impact velocity and angle. It is shown that for perpendicular impact there are fairly simple mathematical models for the spreading diameter and the number of scallops or spines formed around the stain though these have quite limited ranges of validity in their basic form. In particular, predictions for the diameter are best for small droplets impacting at high velocity and the number of spines saturates for higher impact velocities. In the case of spreading, a modification to the energy conservation model is found to provide excellent agreement with experimental stain diameters across a wide range of impact velocities. For non-perpendicular impact, the width of stains is found to depend principally on the normal component of impact velocity and may be predicted by an appropriate modification to the expression for the perpendicular case. Limitations in the calculation of impact angle from the stain aspect ratio are identified and a theoretical basis for the prediction of spines around an elliptical stain is proposed. Some key issues for future research are identified which include a systematic, quantitative study of the effect of surface properties on bloodstain formation.

SEDIMENT SELECTION BY JUVENILE SEA SCALLOPS (CANCER IRRORATUS SAY)

Abstract We examined sediment selection by juvenile sea scallops (Placopecten magellanicus) and their predators, sea stars (Asterias vulgaris) and rock crabs (Cancer irroratus). In laboratory trials, groups of scallops (~30 mm shell height) were simultaneously offered four sediment types in the presence and absence of a sea star or a rock crab: (1) glass representing a homogeneous, hard bottom; (2) sand; (3) granule and (4) pebble. As well, individual predators were offered the four sediment types without scallops. The number of scallops and the proportion of time predators spent on each sediment type were monitored over time. When compared with the expected distribution, scallops avoided glass and tended to select granule and pebble sediments when alone. In the presence of a rock crab, scallops also avoided glass. However, scallop distribution was similar to the expected distribution when a sea star was present, because sea star encounters are an important trigger of scallop swimming, leading to frequent...

Optimisation of Multiple Tool CNC Rough Machining of a Hemisphere as a Genetic Algorithm Paradigm Application

This work presents the development of a method to achieve optimal roughing of a hemisphere in terms of least machining time and maximum material removal from the original material block. This is considered as a problem formulation case study in the field of genetic algorithm applications - a preamble to more complex and generic geometry. A genetic algorithm is used off-the-shelf as an optimisation tool. Three different process parameters are used to model the problem : the number of scallops, the height of each scallop, and the tools used. Multiple tools are considered, in particular their diameters, maximum depths of cut and maximum feed allowed, as defined in a tool database, whereas the strategy of the tool path on each slice (but not the path details) is taken as known. Fitness functions that can be used independently or combined are the cutting time and the remaining material. The proposed method results in a concentrated result table containing the sequence of the tools employed and the corresponding scallop heights.