Freezing Time Research Articles

Turn to Traditions – Calls for Change: Negotiations over Liturgy in the Synagogues of Finland

Abstract This article explores how Jews in Finland relate to the musical traditions of their synagogues and the changes that have occurred in the customs over time and as the result of various cultural and spiritual influences. Based on ethnographic data, it focuses on rituals, liturgy, and music as contexts for negotiating relationships between the institution and the individual, memory practices, and contemporary innovation – being and doing Jewish, to use concepts from the vernacular religion framework. The article outlines the historical development of Minhag Finland, the vernacular liturgical customs. It concludes that the “turn to traditions” should be stated in the plural, as several Jewish customs, cultures, and context are engaged in the negotiations around liturgy. This is not just a way to freeze time and preserve the status quo. Instead, seeking for meaningful models in the past paves the way for change – especially when turning toward a broad range of traditions.

Influence of sucralose, acesulfame-k, and their mixture on brain's fish: A study of behavior, oxidative damage, and acetylcholinesterase activity in Daniorerio

Sucralose (SUC) and acesulfame-k (ACE-K) are widely used artificial sweeteners worldwide; however, they are frequently detected in aquatic environments due to their low metabolism and inadequate removal during wastewater treatment. The harmful effects of these compounds on hydrobionts have yet to be fully understood, as data on their toxicity is limited and inconclusive. This research aimed to determine the impact of SUC (50, 75, 125 μg/L) and ACE-K (50, 75, 125 μg/L), individually and in combination, on fish's swimming behavior, acetylcholinesterase activity, and oxidative stress response after four months of exposure. Following exposure, adult Danio rerio displayed anxiety-like behavior, as evidenced by increased freezing time and decreased swimming activity. Additionally, analysis of fish brain tissue revealed a disruption of REDOX homeostasis, leading to oxidative stress, which may be responsible for the observed inhibition of AChE activity. The results indicated that ACE-K was more toxic than SUC, and the mixture of both compounds produced a more detrimental effect than when each compound was administered alone. These findings highlight the hazardous impacts of SUC and ACE-K on fish in environmentally relevant concentrations, suggesting that these compounds should be added to the priority pollutant list.

Development of novel correlations towards the freezing time estimation of phase change material inside a cylindrical capsule involving thickness and its thermal conductivity for thermal storage applications – An experimental and parametric studies

The freezing of phase change materials (PCM) is a widespread phenomenon with numerous potential applications in fields such as refrigeration, thermal storage, chemical industries, etc. Thermal energy storage (TES) is one such application where the inward freezing concept is utilised during the solidification of a PCM in cylindrical container. Literature shows various correlations to predict the inward and outward freezing duration of PCM inside a cylindrical container. However, no correlation describes the effect of container material properties on the PCM freezing time. Therefore, two new correlations are developed - one for the inward freezing time of PCM inside a cylindrical container and the other for the outward freezing time around it, taking into account the effect of container material thermal conductivity and its thickness. Subsequently, experimental research is conducted to validate the proposed correlation, which agrees with the experimental freezing time, with a maximum inaccuracy of around 7.8 %. Finally, a parametric study analysing the effect of container thermal conductivity and thickness on the inward freezing time of PCM reveals that the thickness of the container plays no role in freezing when container thermal conductivity exceeds 5 W m−1 K−1.

Metoprolol elicits neurobehavioral insufficiency and oxidative damage in nontarget Nauphoeta cinerea nymphs.

Metoprolol, a drug for hypertension and cardiovascular diseases, has become a contaminant of emerging concern because of its frequent detection in various environmental matrices globally. The dwindling in the biodiversity of useful insects owing to increasing presence of environmental chemicals is currently a great interest to the scientific community. In the current research, the toxicological impact of ecologically relevant concentrations of metoprolol at 0, 0.05, 0.1, 0.25, and 0.5 μg/L on Nauphoeta cinerea nymphs following exposure for 42 consecutive days was evaluated. The insects' behavior was analyzed with automated video-tracking software (ANY-maze, Stoelting Co, USA) while biochemical assays were done using the midgut, head and fat body. Metoprolol-exposed nymphs exhibited significant diminutions in the path efficiency, mobility time, distance traveled, body rotation, maximum speed and turn angle cum more episodes, and time of freezing. In addition, the heat maps and track plots confirmed the metoprolol-mediated wane in the exploratory and locomotor fitness of the insects. Compared with control, metoprolol exposure decreased acetylcholinesterase activity in insects head. Antioxidant enzymes activities and glutathione level were markedly decreased whereas indices of inflammation and oxidative injury to proteins and lipids were significantly increased in head, midgut and fat body of metoprolol-exposed insects. Taken together, metoprolol exposure induces neurobehavioral insufficiency and oxido-inflammatory injury in N. cinerea nymphs. These findings suggest the potential health effects of environmental contamination with metoprolol on ecologically and economically important nontarget insects.

Simulation for performance of storage unit with analyzing water freezing in presence of nanoparticles

The influences of loading alumina with different range of diameter and concentration have been considered in this study. The single phase mixture for predicting the features of nanomaterial was incorporated and equations in unsteady form were presented. For deriving the solution of the model, Galerkin method was used incorporating implicit technique. Validation tests have been provided and reasonable accuracy has been obtained. The geometry has tree shape fins which can help to accelerate the process. Although increasing size of powder can augment the interaction of them, the freezing time increases if the size of particles increases greater than 40 nm. Adding nano-powders can decrease the required time by about 41.26 %. With the changing size of nanoparticles, firstly, freezing time decreases about 20.02 % then it increases about 49.33 %. The minimum required time for freezing is 3991.58 s and this period happens when dp = 40 nm and ϕ = 0.04.

Freezing Characteristics of a Water Droplet on a Multiscale Superhydrophobic Surface.

Superhydrophobic surfaces have the potential to retard ice formation owing to their super water-repellant nature arising from high static contact angle and low contact angle hysteresis. Most of the previous studies have focused on patterned surfaces with mono-scaled prismatic structures. In contrast, the freezing behavior on multiscaled rough superhydrophobic surfaces that are of practical significance is relatively little studied. This article presents, for the first time, the freezing dynamics of a water droplet interacting with multiscale fractal superhydrophobic surfaces which validates well with experimental measurements. It is shown that the dual effects of increased contact angle and poor interfacial conduction due to trapped air cavities within the roughness features of the superhydrophobic surface lead to increasing freezing time with increasing surface hydrophobicity, determined as a function of the fractal surface parameters. A comparison of the freezing dynamics of sessile droplets of identical contact angle on a smooth versus a rough superhydrophobic surface shows that interfacial asperity thermal resistance contributes to over 14% increase in the freeze time. It is further shown that by tailoring the multiscale characteristics, the freeze time may be increased by up to 7-fold compared to freezing on a smooth surface. The application of the numerical model to studying ice formation on several practical superhydrophobic surfaces of a range of metallic materials and fabrication methods is also discussed, which offers guidelines for the design of anti-icing surfaces in practice.

Comparison of air freezing, liquid immersion freezing and pressure shift freezing on freezing time and quality of snakehead (Channa Argus) fillets

The objective of this study was to investigate the freezing time and quality differences in Snakehead fillets frozen by pressure shift freezing (PSF), conventional air freezing (AF) and liquid immersion freezing (LIF) at −20 °C, −40 °C and − 60 °C, respectively. The results showed that liquid immersion freezing at −60 °C maintained the quality best, with a freezing time of 3.62 min and the cross sectional area of 209.11 um2. Air freezing at −20 °C had the longest freezing time (184.58 min) and the largest cross sectional area (4470.79 um2), and lowest hardness and springiness of the fillets. Pressure shift freezing did not demonstrate the well established advantages of maintaining better product quality found in similar technique with some other foods. The samples of pressure shift freezing also had higher thawing loss and free water ratio after thawing. Therefore, the liquid immersion freezing at lower temperatures was demonstrated to better maintain the quality of frozen products and held significant potential for commercial application. Industrial relevanceFreezing is a widely used method for extending the shelf life of aquatic products, but some freezing methods, especially the slower ones, often lead to the decrease in the quality and commercial value of frozen products during storage. This paper explored the comparison of industrially used freezing techniques (air freezing and liquid immersion freezing) with the novel pressure shift freezing technique. Liquid immersion freezing at −60 °C was found to be the preferred freezing method for Snakehead fillets, which maintained better frozen product quality, with a simple freezing process and low cost.

Temporal and Spatial Evolution Laws of Freezing Temperature Field in the Inclined Shaft of Water-Rich Sand Layers

This study investigated the distribution and evolution characteristics of the temperature field during the freezing and excavation of inclined shafts, with the freezing open-excavation section of Shengfu Mine’s main inclined shaft (located in Shaanxi Province) as the project background. Utilizing field-measured data and the finite element software COMSOL Multiphysics, a 3D freezing temperature-field numerical calculation model was constructed to examine the temporal and spatial evolutions of the temperature field during the construction of the inclined shaft. The findings showed that after 88 days of freezing, the average temperature of the frozen wall in the open-excavation section was below −12 °C. The frozen wall thickness in the sidewalls of different layers exceeded 4 m, and the thickness at the bottom plate exceeded 5 m, meeting the excavation design requirements. For the same freezing time, the average temperature of the frozen wall in the fine sand layer was 0.28 to 2.39 °C lower than that of the frozen wall in the medium sand layer, and its effective thickness was 0.36 to 0.59 m greater than that in the medium sand layer. When the soil was excavated, and the well side was exposed, a phenomenon known as “heat flow erosion” occurred in the soil at the well-side position, causing the well-side temperature to rise. Nevertheless, this increase was generally limited, and when continuous cooling was applied, the well side could maintain a very low negative temperature level. Consequently, there was no spalling phenomenon. The effective thickness of the frozen wall during excavation did not decrease, with the average temperature remaining below −10 °C. Consequently, there was no large-scale “softening” of the frozen wall during excavation, thus ensuring construction safety. The numerical calculation model in this paper can be used to predict the development law of the freezing temperature field of the water–rich sandy layers in Shengfu Mine and adjust the on–site cooling plan in real time according to the construction progress. This research provides valuable theoretical insights for the optimal design and safe construction of freezing inclined-shaft sinking projects.

Effects of magnetic field-assisted liquid carbon dioxide spray freezing on the quality of honeydew melon.

The effectiveness of static magnetic fields with different intensities (5, 10, 15 mT) combined with liquid carbon dioxide spray freezing (LCSF) technique in improving the quality of frozen honeydew melon was investigated. The results showed that LCSF with magnetic fields above 10 mT significantly improved ice nucleation and quality of frozen melons compared to conventional -20°C freezing, -80°C freezing and LCSF method without magnetic field assistance (P<0.05). 15 mT strength static magnetic field assistance suggested the best results, with a 15.0% reduction in total freezing time, 17.7% increase in average freezing rate, 26.6% reduction in drip loss, and better maintenance of sample quality compared to LCSF. These findings demonstrate that LCSF with static magnetic field assistance is promising in improving the quality of frozen foods.

Comparison of anxiolytic effects of mammalian and bony fish kisspeptins in &lt;dfn&gt;Danio rerio&lt;/dfn&gt;

In our previous work, we suggested that analogs of mammalian kisspeptin Kiss1 reduce anxiety and phobic reactions novel in Danio rerio. The most effective dose for the action of the studied analogs of kisspeptin corresponded to 0.1 mg per 1000 mL of water. In this study, other analogs of mammalian Kiss1 at a dose of 0.1 mg per 1000 mL of water also reduced the anxious behavior of Danio fish. The effect of Kiss1 and Kiss2 kisspeptins on the behavior of Danio rerio was also evaluated. In the novel test, the number of freezing decreased by two times with the introduction of kisspeptin 10 and by three times after the introduction of the kisspeptin analog. An analog of mammalian kisspeptin reduced the freezing time by two times. The length of the trajectory decreased by two times under the influence of the mammalian Kiss1 kisspeptin analog. With the action of kisspeptin 10, the number of transitions to the upper part of the tank increased by two times. After the introduction of the kisspeptin analog, the number of transitions to the upper part of the aquarium increased by three times. In the predator test, the number and time of freezing decreased by 1.5 times with the action of mammalian kisspeptins. The length of the trajectory after the introduction of kisspeptin bony fish and kisspeptin 10 mammals increased. The length of the trajectory after the introduction of Kiss1 increased by 1.5 times. The length of the trajectory after the introduction of Kiss2 increased by three times. After the introduction of kisspeptin 10, the trajectory increased by two times, and the time spent in the lower part of the tank decreased by two times. Kisspeptins of bony fish also reduced the anxiety and phobic reactions in fish, but to a lesser extent. Thus, kisspeptin 10 and an analog of mammalian kisspeptin in response to the presentation of a predator had more significant effects on anxiety in Danio rerio compared with the action of kisspeptin bony fish Kiss1 and Kiss2. Thus, bony fish kisspeptins and mammalian kisspeptins can reduce anxiety and phobic reactions in Danio rerio; however, mammalian kisspeptins are the most effective. Bony fish kisspeptin Kiss1 has an anxiolytic effect in contrast to Kiss2, which suggests that it affects fear reduction, and Kiss2 appears to be responsible for social and sexual behavior. The results support the hypothesis that kisspeptins may be involved in the regulation of anxiety and phobic states, apparently to maintain the emotional aspects of reproductive behavior, such as sexual motivation and arousal.

Study on the performance enhancement of ice storage and melting processes in an ice-on-coil thermal energy storage system

Air conditioners equipped with an ice storage system store a large amount of latent heat during the off-peak period at night, and use the stored cold energy for the air conditioner during the peak period of the day, thereby greatly reducing peak power consumption. In this study, an experimental analysis was conducted to evaluate the cold storage and cooling characteristics of an ice-on-coil storage system. Firstly, the influence of the inlet brine temperature, flowrate, and concentration on the discharge rate was studied. It was observed that all parameters were directly proportional to the discharge rate, and the effect of brine inlet temperature was more pronounced. Secondly, the alumina nanofluid as a phase change material was employed in the system for enhancing the thermal performance. The experimental results showed that using nanofluid shortened the freezing time, while it had a negative impact on the thermal behavior during the ice melting. Thirdly, the ice storage coils with spiral fins were used. It was concluded that the employment of finned coils reduced the melting time by 24.0 %, increased the average discharge rate by 74.4 %, and raised the cumulative discharge capacity by 63.5 % compared with original bare coil design.

Experimental and Numerical Study of the Ice Storage Process and Material Properties of Ice Storage Coils

The coiled ice-storage-based air conditioning system plays a significant role in enhancing grid peak regulation and improving cooling economy. This paper presents theoretical and experimental studies conducted on the ice storage process of coiled ice storage air conditioning technology. The cooling of water is divided into two stages:10.0 °C to 4.0 °C and 4.0 °C to below 0.0 °C. Initially, the ice storage process forms an ice layer with a thickness of 2.50 mm on the lower surface of the coil, but eventually, the ice layer on the upper surface becomes 3.85 mm thicker than the lower surface as a result of the natural convection of water and density reversal at 4.0 °C. Furthermore, the impact of three coils with different thermal conductivity on the ice storage process was evaluated. It was observed that the thermal conductivity of R-HDPE (reinforced high-density polyethylene) was only 2.6 W/(m·K) higher than HDPE (high-density polyethylene), yet it reduced the freezing time by 34.85%, while the thermal conductivity of steel was 37.4 W/(m·K) higher than R-HDPE, but only decreased the freezing time by 9.40%. The results demonstrated that the rate of ice accumulation increased with thermal conductivity. However, when the coil material’s thermal conductivity surpassed that of ice, the further increase of thermal conductivity gradually weakened its impact on the ice storage rate.

Transcriptome Analysis Reveals Brassinolide Signaling Pathway Control of Foxtail Millet Seedling Starch and Sucrose Metabolism under Freezing Stress, with Implications for Growth and Development.

Low-temperature stress limits the growth and development of foxtail millet. Freezing stress caused by sudden temperature drops, such as late-spring coldness, often occurs in the seedling stage of foxtail millet. However, the ability and coping strategies of foxtail millet to cope with such stress are not clear. In the present study, we analyzed the self-regulatory mechanisms of freezing stress in foxtail millet. We conducted a physiological study on foxtail millet leaves at -4 °C for seven different durations (0, 2, 4, 6, 8, 10, and 12 h). Longer freezing time increased cell-membrane damage, relative conductance, and malondialdehyde content. This led to osmotic stress in the leaves, which triggered an increase in free proline, soluble sugar, and soluble protein contents. The increases in these substances helped to reduce the damage caused by stress. The activities of superoxide dismutase, peroxidase, and catalase increased reactive oxygen species (ROS) content. The optimal time point for the response to freezing stress was 8 h after exposure. The transcriptome analysis of samples held for 8 h at -4 °C revealed 6862 differentially expressed genes (DEGs), among which the majority are implicated in various pathways, including the starch and sucrose metabolic pathways, antioxidant enzyme pathways, brassinolide (BR) signaling pathway, and transcription factors, according to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment. We investigated possible crosstalk between BR signals and other pathways and found that BR signaling molecules were induced in response to freezing stress. The beta-amylase (BAM) starch hydrolase signal was enhanced by the BR signal, resulting in the accelerated degradation of starch and the formation of sugars, which served as emerging ROS scavengers and osmoregulators to resist freezing stress. In conclusion, crosstalk between BR signal transduction, and both starch and sucrose metabolism under freezing stress provides a new perspective for improving freezing resistance in foxtail millet.

Numerical investigation of the effect of rectangular and semicircular cavities filled with phase change materials installed on the solar wall

The use of alternative energy sources, particularly solar energy, in buildings is rising and spreading around the globe. In this paper, a solar wall is analyzed using a numerical method. On the wall, a number of obstacles are placed in two shapes, rectangular (REC) and semicircular (SEC). The cavities are filled with organic phase-change materials. This study was performed in 7 h in the absence of solar radiation on the wall for different dimensions of obstacles in 5 different modes. Various temperatures have been investigated, including exhaust air temperature (TAR), Trombe wall temperature (TWL), and mean volume % of molten PCM in cavities. COMSOL software is used to carry out this numerical study. The results of this study showed that the use of SECs compared to RECs causes the TWL to be higher. In the most extreme case, at a 16 cm aspect ratio, the use of SECs gives a 2.1 °C increase in TWL relative to the REC one. The outlet TAR is also increased by the usage of SECs. The use of larger dimensions of the cavities has increased the TAR leaving the wall so that the TAR after 7 h of the absence of solar radiation, in the most significant case of SECs, was more than 295.5 K. The use of SECs also increases the PCM freezing time. In the largest case of cavities, using SECs increases the freezing time by 15 min compared to RECs.

Effect of Freezing on Soybean Protein Solution.

To investigate the impact of frozen storage conditions on the physicochemical properties of soybean protein and explore the underlying mechanisms, this study focused on soybean isolate (SPI), ß-soybean companion globulin (7S), and soybean globulin (11S). The protein solutions were prepared at a concentration of 2% and subjected to freezing for 1 and 5 days. Subsequently, the protein content, physicochemical properties, secondary structure, sulfhydryl content, and chemical interaction forces were assessed and analyzed using UV spectrophotometry, Zeta potential measurements, SDS-PAGE, Fourier infrared spectroscopy, and endogenous fluorescence photoemission spectroscopy. The obtained results revealed that the solubility and total sulfhydryl content of SPI, 7S, and 11S exhibited a decreasing trend with prolonged freezing time. Among them, 11S demonstrated the largest decrease in solubility and total sulfhydryl content, followed by SPI, and 7S the least. During freezing, the aromatic amino acids of SPI, 7S, and 11S molecules were exposed, leading to increased hydrophobicity, protein aggregation, and particle size enlargement, and the structure of the protein changed from disordered structure to ordered structure. After freezing, the polarity of the microenvironment of SPI, 7S, and 11S increased, and their maximum fluorescence emission wavelengths were red-shifted. Notably, the largest red shift of SPI was from 332 nm to 335 nm. As freezing time increased, the contribution of hydrogen bonding increased, while the contribution of hydrophobic interactions decreased. This indicates that freezing affects the hydrophobic interactions, hydrogen bonding, and other chemical forces of the protein. The growth of ice crystals leads to the unfolding of protein molecular chains, exposure of internal hydrophobic groups, enhancement of hydrophobicity, and alters the secondary structure of the protein.

Extraction of glucomannan from porang (Amorphophallus muelleri Blume) with freeze-thaw cycles pre-treatment

Amorphophallus muelleri Blume tuber, which is called porang in Indonesia, is one of the biggest glucomannan sources next to the konjac tuber. Glucomannan is commonly produced by ethanol extraction technique. This study aimed to propose the freeze-thaw cycles (FTC) pre-treatments with two factors including freezing time and the number of cycles before the glucomannan extraction step and investigated the impact on the physicochemical and morphological properties of the extracted glucomannan. The obtained data were statistically tested by means of multivariate analysis of variance (MANOVA) and post-hoc Duncan tests at a significance level (P) of 0.05. The treated samples were statistically compared with the control sample (without FTC) by means of the Dunnett’s test. The result showed that FTC pre-treatments changed the morphology of glucomannan from smooth to become porous globes showing more fissures on its surface. Generally, the freezing time treatments affected the physicochemical properties of glucomannan except for its protein and calcium oxalate contents. The number of cycles did not significantly affect the protein, starch, and calcium oxalate contents. The Dunnett’s test results indicated that the ash, carbohydrate (glucomannan), and color of the glucomannan obtained by the FTC pre-treatments were significantly different from those of the control sample.

The influence of tunnel insulation measures on the temperature spatiotemporal variation of frozen soil during artificial ground freezing

Artificial ground freezing (AGF) has been widely used in the construction of subway connection channels to reinforce the soil around the tunnel, especially the water-rich soft soil, to ensure the stability of the tunnel and the overlying buildings. However, the direct contact between the frozen soil curtain and the tunnel segment would cause the loss of cooling capacity, which is not conducive to ensuring the freezing effect. The indoor freezing and thawing model of silty soft soil was established to explore the influence of tunnel insulation measures with different thermal conductivity on the temperature spatiotemporal variation of frozen soil curtain through indoor simulation tests. The effects of thermal insulation materials with different thermal conductivity on the stable temperature and development speed of frozen soil curtains were also compared. The results indicated that the interface of tunnel segments has a significant impact on the freezing speed and stable temperature of frozen soil during the freezing process, as well as the thawing time during the natural thawing process. Compared with steel segment tunnel, the use of thermal insulation coating with low thermal conductivity increased the temperature of the soil at the same distance by 5.88% to 42.5%, and prolonged the freezing time of the soil far from the tunnel by 38.8%. On the contrary, the insulation foam with higher thermal conductivity not only reduced the temperature of frozen soil by 13.8% at most, but also shortened the freezing time by 42.1% at most, which can significantly improve the construction efficiency. For the natural thawing process, the thermal insulation coating would reduce the thawing time of frozen soil by more than 30%, while the thermal insulation foam can increase the thawing time of frozen soil far away from the tunnel by at least 23%, which was more conducive to extending the allowable duration of frozen soil excavation. The results can provide a reference for the selection of segment insulation measures in the AGF construction of subway cross channels in silty soft soil.

Comparison of immersion freezing, osmo‐dehydrofreezing and air freezing on freezing parameters and physicochemical properties of mango (Mangifera indica L.)

SummaryEffects of immersion freezing (IF), osmo‐dehydrofreezing (ODF) and air freezing (AF) on freezing parameters and physicochemical properties of frozen mango were studied. Results showed that IF had the shortest freezing time, followed by ODF and AF. In ODF groups, dehydrofreezing in 50% glucose (G‐50) showed the highest quality. Mangoes pre‐treated in glucose had higher quality than those pre‐treated in trehalose. The quality of osmo‐dehydrofrozen mangoes was more affected by freezing rate than by difference between freezing temperature and the glass transition temperature (T−). Compared with the AF, IF in 60% ethylene glycol (EG‐60) and ODF in G‐50 significantly improved the quality of mangoes, including colour change and drip loss reduced by 43.7%, 28.6%, 41.4% and 19.6%, hardness increased by 540.7% and 413.6%, and contents of vitamin C and total phenol increased by 30.7%, 24.3%, 18.3% and 6.4%, respectively. Overall, IF in EG‐60 was the most favourable method for frozen mangoes.

Behavioral Study of 3- and 5-Halocytisine Derivatives in Zebrafish Using the Novel Tank Diving Test (NTT)

Anxiety is a serious mental disorder, and recent statistics have determined that 35.12% of the global population had an anxiety disorder during the COVID-19 pandemic. A mechanism associated with anxiolytic effects is related to nicotinic acetylcholine receptor (nAChR) agonists, principally acting on the α4β2 nAChR subtype. nAChRs are present in different animal models, including murine and teleosteos ones. Zebrafish has become an ideal animal model due to its high human genetic similarities (70%), giving it high versatility in different areas of study, among them in behavioral studies related to anxiety. The novel tank diving test (NTT) is one of the many paradigms used for studies on new drugs related to their anxiolytic effect. In this work, an adult zebrafish was used to determine the behavioral effects of 3- and 5-halocytisine derivatives, using the NTT at different doses. Our results show that substitution at position 3 by chlorine or bromine decreases the time spent by the fish at the bottom compared to the control. However, the 3-chloro derivative at higher doses increases the bottom dwelling time. In contrast, substitution at the 5 position increases bottom dwelling at all concentrations showing no anxiolytic effects in this model. Unexpected results were observed with the 5-chlorocytisine derivative, which at a concentration of 10 mg/L produced a significant decrease in bottom dwelling and showed high times of freezing. In conclusion, the 3-chloro and 3-bromo derivatives show an anxiolytic effect, the 3-chlorocytisine derivative being more potent than the 3-bromo derivative, with the lowest time at the bottom of the tank at 1mg/L. On the other hand, chlorine, and bromine at position 5 produce an opposite effect.

Pengaruh Teknik Pembekuan Ikan Tongkol (Euthynnus affinis) Terhadap Organoleptik di PT. Aceh Lampulo Jaya Bahari

Tuna contains high protein so that it fulfills the nutritional needs of the human body. Tuna is a marine fish that contains omega 3, vitamins, protein and minerals. This study aims to determine the effect of the freezing technique of tuna (Euthynnus affinis) on organoleptic at PT.Aceh Lampulo Jaya Bahari using a temperature of -30oC to -40oC with a freezing time of about 8 - 12 hours. Methods This study used a qualitative method consisting of research on the first with the influence of the technique of freezing tuna (Euthynnus affinis) with a comparison of 3 freezing methods, the second stage carried out an organoleptic analysis (ice layer, dehydration, discoloration, appearance, smell, texture.) on frozen tuna. The results of the value of the ice layer showed that the most preferred value by the analyst was the value of the semi contact plate freezer 7 ± 0.67 and cold storage 7 ± 0.67, the dehydration indicated the value most preferred by the analyst was the value of the semi contact plate freezer 7 ± 0.67 and cold storage 7 ± 0.67. The result of the value of dehydration shows the value most preferred by the analyst is the value of the semi contact plate freezer 7 ± 0.78. The result of the value of the appearance shows the value most preferred by the analyst is the value of air blast freezer 7 ± 0.50. the result of the value of the appearance shows the most preferred value by the analyst is the value of the air blast freezer 7 ± 0.50, the result of the value of the odor shows the most preferred value by the analyst is the value of the semi contact plate freezer 7 ± 0.41 and cold storage 7 ± 0.41, the value of the texture shows the most preferred value by the analyst is the value of air blast freezer 7 ± 0.25, semi contact plate freezer 7 ± 0.25 and cold storage 7 ± 0.25.