Squid Fin Research Articles

Cooling characteristics of nanofluids in a snowflake and squid fin composite bionic microchannel heat sink

To improve the heat dissipation performance of electronic components, this study proposed a novel biomimetic microchannel design inspired by snowflakes and squid fins. A numerical simulation method was employed to investigate the cooling characteristics of nanofluids at different concentrations within this biomimetic microchannel heat sink. The microchannel is shaped like a snowflake, while the base plate features a biomimetic squid fin structure. The study focused on analyzing the effects of waveform height (amplitude A = 0.1–0.4 mm) and waveform frequency (B = 0.5–2π) on heat transfer performance. The results indicated that when nanofluids flow over a base plate with a wavelength frequency of B = 0.5π, there is a significant enhancement in heat exchange while simultaneously reducing flow resistance. In the microchannel heat sink (A = 0.3 mm, B = π), the thermal conductivity of the nanofluids can be increased by up to 32.56 %, with a maximum comprehensive evaluation index of 1.68. This research provides important guidance for the application of nanofluids and biomimetic microchannels in the thermal control of electronic devices.

Quantifying fin shape in Brachioteuthis beanii (Cephalopoda: Brachioteuthidae) collected at The Gully Marine Protected Area, off Nova Scotia, Canada

Oegopsid squid fin shape changes with ontogeny and identifying the timing of these changes may distinguish between phases and stages of cephalopod life cycles. Fin shape of Brachioteuthis beanii was analyzed in 67 specimens (41–105 mm ML) divided into 5 groups based on size and sex. Male and female adult fins are the same shape, but the adult shape is different from juvenile and subadult shape. The Angle of Maximum Height and Width were similar across B. beanii in the size groups treated (AMxH =16 ± 2°and AMxW= 70 ± 3°). In brachioteuthids, the difference between a saggitate fin and a rhomboidal fin may be a function life cycle phase.

Threadfin bream surimi gel containing squid fin protein hydrolysate: Textural properties, acceptability, and volatile profile.

Gel properties of threadfin bream surimi gels with squid fin protein hydrolysate (SFPH) at various concentrations (0, 1, 2, 3, and 4%; w/w) were determined. The gel without SFPH (CON) had the highest breaking force (BrF) and deformation (DeF) as compared to those with SFPH (p<0.05). Among the gel with SFPH, gel containing 1 and 2% SFPH (SFPH-1 and SFPH-2, respectively) had the highest BrF, whereas the lowest value was obtained when 4% SFPH was used (SFPH-4) (p<0.05). The whiteness of all samples was slightly decreased with an upsurging amount of SFPH. However, water holding capacity was increased with augmenting levels of SFPH (p<0.05). Sensory analysis revealed that SFPH-2 had a higher squid odor and flavor likeness score than CON (p<0.05). Textural properties, especially hardness, were decreased with increasing SFPH, except for SFPH-1 and SFPH-2 (p>0.05). In addition, the rheological properties, microstructure, and volatile profile of the selected surimi gel were also studied. The storage modulus (G') of SFPH added samples was decreased as compared to the CON sample. The CON gel had a finer and more compact network as compared to SFPH-2 and SFPH-4 samples. Volatile profiles indicated that alcohols, carboxylic acids, ketones, and ether were the major volatile compounds present in both gel samples. Furthermore, thiophene, 3-methyl-, contributing to squid flavor, was found in the SFPH-2 sample. Overall, SFPH at 2% could act as a flavorant in the threadfin bream surimi gel without markedly negative impact on gelling and textural properties, while providing squid odor and flavor to the resulting gel. PRACTICAL APPLICATION: The various low-valued byproducts generated from the squid processing industry could result in various environmental problems. Those byproducts are rich in various biomolecules such as proteins, fats, enzymes, and so forth, which could be utilized to produce value-added products. Among them, protein hydrolysate (PH) rich in amino acids with excellent antioxidant properties could serve as an alternative flavorant. Therefore, PH from squid byproducts, especially fins, could be applied in foods such as fish balls, surimi gels, and so forth to enhance the nutritional and flavoring profile of a finished product. Moreover, bioactive peptides in PH with antioxidant potential could retard the oxidation of proteins and lipids.

Protein Hydrolysate from Splendid Squid (Loligo formosana) Fins: Antioxidant, Functional Properties, and Flavoring Profile

Protein hydrolysates (PH) from splendid squid fins (Loligo formosana) (SFPH) with different degrees of hydrolysis (DH) (10-40%) were prepared using alcalase and characterized. The yield of SFPH was increased with increasing DH (p&lt;0.05). All SFPHs showed high protein content but low fat and ash contents. The lightness of SFPH was reduced with augmenting DH as advocated by increasing redness and yellowness (p&lt;0.05). All SFPH samples having DH above 10% exhibited relative solubility higher than 90% (p&lt;0.05). Foaming properties of SFPH were also improved with increasing DH. In general, antioxidant activities upsurged with increasing DH, except metal chelating activity and DPPH radical scavenging activity, which were decreased at higher DHs. Molecular weight (MW) of peptides was lowered with increasing DH as measured by size exclusion chromatography and SFPH having DH 40% (SFPH-40) possessed a higher proportion of peptides with smaller MW. SFPH-40 was rich in aspartic acid/asparagine and glutamic acid/glutamine. SFPH-40 had bitterness, especially at high concentrations. SFPH-40 contained a high number of volatile compounds associated with squid flavor. Thus, hydrolysates from squid fin could serve as an alternative nutrient with flavoring characteristics and antioxidant properties for food applications.

Effect of squid fin bionic surface and magnetic nanofluids on CPU cooling performance under magnetic field

AbstractIn order to improve the low cooling efficiency of electronic component, a squid fin bionic surface and composite magnetic nanofluids were developed and applied in CPU cooling. Effects of squid fin bionic surface and composite nanofluids Fe3O4‐CNTs (FCNT)/water nanofluids on CPU cooling performance under magnetic field were systematically studied. The impacts of nanofluids mass fraction, wave frequency of squid fin bionic surface, magnetic induction intensity, and Reynolds number on the flow and heat exchange characteristics of magnetic nanofluids were considered. The experimental results demonstrated that the cooling capacity of magnetic nanofluids increases with the increasing wave frequency, magnetic induction intensity, and nanofluids mass fraction. Lastly, the whole experimental system was evaluated by a comprehensive performance index, and it was found that the comprehensive performance is better with higher wave frequency and stronger magnetic field.

New approaches for assessing squid fin motions: coupling proper orthogonal decomposition with volumetric particle tracking velocimetry.

Squid, which swim using a coupled fin/jet system powered by muscular hydrostats, pose unique challenges for the study of locomotion. The high flexibility of the fins and complex flow fields generated by distinct propulsion systems require innovative techniques for locomotive assessment. For this study, we used proper orthogonal decomposition (POD) to decouple components of the fin motions and defocusing digital particle tracking velocimetry (DDPTV) to quantify the resultant 3D flow fields. Kinematic footage and DDPTV data were collected from brief squid, Lolliguncula brevis [3.1-6.5 cm dorsal mantle length (DML)], swimming freely in a water tunnel at speeds of 0.39-7.20 DML s-1 Both flap and wave components were present in all fin motions, but the relative importance of the wave components was higher for arms-first swimming than for tail-first swimming and for slower versus higher speed swimming. When prominent wave components were present, more complex interconnected vortex ring wakes were observed, while fin movements dominated by flapping resulted in more spatially separated vortex ring patterns. Although the jet often produced the majority of the thrust for steady rectilinear swimming, our results demonstrated that the fins can contribute more thrust than the jet at times, consistently produce comparable levels of lift to the jet during arms-first swimming, and can boost overall propulsive efficiency. By producing significant drag signatures, the fins can also aid in stabilization and maneuvering. Clearly, fins play multiple roles in squid locomotion, and when coupled with the jet, allow squid to perform a range of swimming behaviors integral to their ecological success.

Collagen from jumbo squid fin: extracting conditions and influence of the protease system on collagen hydrolysate antioxidant activity

The optimal alkaline and acid conditions for insoluble collagen extraction from jumbo squid fin (JSF) were established by factorial analysis. Dependent variable: protein concentration; independent variables: NaOH and HCl concentrations. The antioxidant properties of JSF collagen hydrolysates obtained by two protease systems were studied. Moreover, jumbo squid skin (JSS) collagen was obtained and hydrolysated under optimal conditions. The optimal extraction condition was 0.5 M NaOH followed by 0.2 M HCl. Collagen α-chains were detected in both JSF and JSS. Collagen β-component was detected only in JSS. JSS collagen showed higher levels of polar and hydrophobic amino acids. The JSF hydrolysates produced by subtilisin showed a lower degree of hydrolysis and higher antioxidant activity (2,2-diphenyl-1-picrylhydrazyl (DPPH), Trolox equivalent antioxidant capacity (TEAC), and oxygen radical absorbance capacity-fluorescein (ORACFL)) than those produced by a mixture of trypsin, chymotrypsin, and peptidase. The JSS hydrolysates showed a higher antioxidant capacity. We have thus established a suitable process to improve the utility of JSF.

PROTEIN SOLUBILITY AND PRODUCTION OF GELS FROM JUMBO SQUID

Solubility at several ionic strengths (0 to 1.0 M), pH (2 to 13) and gelling capacity of jumbo squid Dosidicus gigas muscle proteins were evaluated. Protein recovery was >90% at pH 9–12. Autohydrolysis was evaluated and affected only sarcoplasmic proteins. Folding score was 5 on all gels. Strength was higher for thermal gels prepared from squid fin (50.2 ± 1.2 N) than that prepared from the mantle (23.4 ± 2.5 N). There was no significant difference in gel strengths from previously frozen (46.4 ± 7.5 N) and never-frozen samples (43 ± 5.5 N). Moisture, water drip and water-holding capacity were evaluated on thermal gels. There were significant differences between frozen and never-frozen samples. Results on solubility and gel forming capacity of the proteins from mantle and fin of jumbo squid suggest that these properties can provide additional value to this resource. PRACTICAL APPLICATIONS Jumbo squid is a rich source of high-quality protein. Obtaining sophisticated products would be an easy way to take advantage of the high-quality proteins in jumbo squid muscle. Knowledge of the functional properties of those proteins is needed to achieve this. The use of such properties, such as gel-forming capacity, which are similar to other proteins used in the food industry, will give jumbo squid added value. The results described here indicate that jumbo squid proteins may be useful as a food ingredient because of their solubility and gel-forming capacity.

Ribosomal RNAs synthesized by isolated squid nerves and ganglia differ from native ribosomal RNAs.

The large rRNA of the squid comprises two chains that may be dissociated by heating at 65 degrees C. A single chain constitutes the small rRNA. Surprisingly, the RNAs synthesized by dissected squid fin nerves and stellate nerves and ganglia differed in size from native rRNAs and did not manifest thermal instability. Nonetheless, they resembled native rRNAs in relative abundance, subcellular distribution, lack of poly(A), and metabolic stability. In addition, newly synthesized RNA was localized in nerve and glial cells, as shown by autoradiographic analysis, and was assembled into 80S ribosomes, which supported the synthesis of neuron-specific neurofilament proteins. Following incubation of nerves and ganglia for >10 h, native rRNAs started to disappear, while two major newly synthesized RNAs progressively accumulated. As a result, after 20 h, native rRNAs were substituted by the two novel RNAs. With use of 32P-cDNA synthesized from the latter RNAs as a probe, the novel RNAs demonstrated a considerable degree of homology with native rRNA in northern analysis. Taken together, the data suggest that in dissected squid nerves and ganglia, the synthesis of native rRNAs is gradually terminated while two novel rRNAs are being synthesized, presumably as a correlate of reactive gliosis and/or neuronal degeneration/regeneration.

Change in Optical Activity Associated With Impulses in Squid Fin Nerves.

Change in Optical Activity Associated With Impulses in Squid Fin Nerves.

Properties of synaptic transmission at the neuromuscular junction of the squid, Loligo opalescens

1. 1. Spontaneous and evoked synaptic activity were recorded from the muscles of squid fin and mantle. These spontaneous synaptic potentials were large (up to 30 mV) and pleomorphic. Their amplitudes were not normally distributed, nor did they appear to be clustered in integral multiples of some “unit” event size. 2. 2. Electrical stimulation of the nerve resulted in muscle twitches when the bath calcium concentration was a third normal or higher. The frequency of spontaneous synaptic events was unaffected by low calcium. 3. 3. The large size of spontaneous events may mean that the synchronized release of only a few such “quanta” are sufficient to cause muscle action potentials and contraction. 4. 4. The shapes of spontaneous events correlated poorly with their amplitudes, which is consistent with release from multiple synaptic sites with distinct properties.

Inhibition of choline acetyltransferase activity in squid giant axon

Using a sensitive radiometric assay the choline acetyltransferase (acetyl-CoA: choline O-acetyltransferase, EC 2.3.1.6) activities of the squid fin nerve, giant axon, axoplasm, and axon envelope were determined. Hexamethylene-1-[4(1-naphthylethenyl)pyridinium]-6-trimethyl ammonium bromide (Compound I) inhibited 94 and 88% of choline acetyltransferase in the intact giant axon at 5 · 10 −3 and 5 · 10 −4 M, respectively, when experiments were conducted in the dark. Exposure of solutions of the inhibitor to light caused inactivation (5 · 10 −3 M gave only 33% inhibition). Compound I (5 · 10 −3 M) depolarized the axon and blocked conduction equally well in the light and dark. Another choline acetyltransferase inhibitor 4-(1-naphthylethynyl)pyridine methiodide (Compound III) had similar effects as described for Compound I except that its potency as a choline acetyltransferase inhibitor was not inactivated by light. Pretreatment of the axon with 25 μg/ml of cottonmouth moccasin venom caused a 5-fold potentiation of the ability of Compounds I and III to block conduction, whereas the venom did not affect the choline acetyltransferase inhibition produced by these compounds. Compounds I and III (1 · 10 −3 M) did not alter the maximal number of stimuli the squid axon could conduct when stimulated at 100 per second or when repetitively firing due to decreasing divalent cation content of media. It is concluded that block of conduction and inhibition of choline acetyltransferase, by these compounds, are separate unrelated effects.