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1.
Small ; : e2405424, 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-39252652

RESUMEN

Air conditioners, being an indispensable component of contemporary living, consume a significant amount of electricity every year. The accumulation of frost, dust, and water on the fins surface hinders the efficiency of the heat exchange process, thereby reducing the effectiveness of the air conditioning system. To address these limitations, this paper proposes a large-scale and cost-effective method combining compression molding, chemical etching, and spray coating to fabricate aluminum fins (HMNA) with hierarchical interlocking structures. The HMNA exhibits outstanding durability, passive and active anti-icing, anti-frosting and defrosting, and self-cleaning capabilities associated with the robust super-hydrophobicity. The hierarchical interlocking structure effectively enhances the physical and environmental durability of the HMNA. Most significantly, the frost time of the HMNA fins assembled heat exchanger is significantly delayed by ≈700% compared to the traditional Al fins heat exchanger, while the frost layer thickness is reduced by ≈75%. This greatly reduces the frequency with which the defrosting cycle is started, thus effectively improving the efficiency of the air conditioning system. The proposed method for economical and mass production of the HMNA fins can be an excellent candidate for the development of low energy consumption air conditioning system.

2.
Int J Vet Sci Med ; 12(1): 101-124, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39239634

RESUMEN

Studying scute and fin morphology are advantageous approaches for phylogenetic identification and provide information on biological linkages and evolutionary history that are essential for deciphering the fossil record. Despite this, no prior research has precisely characterized the histological structures of scutes in the common pleco. Therefore, this research investigated the microstructure and organization of bone tissue within the dermal skeleton, including the scutes and fins, in the common pleco, using light microscopy, stereomicroscopy, and scanning electron microscopy. The dermal scutes were organized in a pentagonal shape with denticular coverage and were obliquely aligned with the caudal portion pointing dorsally. The dermal scutes consisted of three distinct portions: the central, preterminal, and terminal portions. Each portion comprised three layers: a superficial bony plate, a basal bony plate, and a mid-plate. Both the superficial and basal bony plates were composed of lamellar bone and lamellar zonal bone, whilst the mid-plate consisted of secondary osteons and woven bone. In the terminal portion, the superficial and basal bony plates became thinner. The pectoral fin consists of spines and rays composed of lepidotrichium (two symmetrical hemi-rays). The spine contained centrifugal and centripetal lamellar and trabecular bones. A centripetal fibrous bone was implanted between the lamellar bones. Besides being oriented in a V shape, the hemi-rays were also composed of thin centrifugal and centripetal lamellar bones and trabecular bones. A fibrous bone was identified between the centrifugal and centripetal bones. The trabecular bone and lamellar bone were made up of bone spicules.

3.
Artículo en Inglés | MEDLINE | ID: mdl-39115629

RESUMEN

Ray-finned fishes (Actinopterygii) represent the most diverse vertebrate lineage that show extensive variations in physiology, ways of life, and adaptations to marine and freshwater environments, and several species have been established as biological research models. The in vitro culture of cells is fundamental for several fields of biological research, being an alternative for studies that use animals. Hundreds of fish cell lines have been established using specific methods for each cell type and species. Here is described a protocol which can be used commonly for obtaining cell cultures from the caudal fin of a wide range of ray-finned fishes including marine and freshwater species. Conditions for sample collection, microbial disinfection, tissue dissociation, plating and incubation, cryopreservation and thawing, and karyotyping are described in detail. Primary cell cultures were developed for 20 species grouped into 12 different orders. Eleven of these species have been cultivated in vitro for the first time. In the beginning, the fish cell cultures showed different capacities of proliferation among them; however throughout the passages, most cultures began to have a similar proliferation rate. Throughout the passages, it was noticed that cells similar to fibroblasts began to predominate. The great proliferative ability of these cultures reveals their potential to become cell lines. The culture of A. mexicanus, for example, has been proliferating for months and is already in its 65th passage. Moreover, these cell cultures showed conserved diploid chromosome numbers in comparison with in vivo descriptions which suggest these cultures have stable karyotypes. Therefore, these cultures have potential to be used in several fields, such as toxicology, cytogenetics, genomics, pathology, immunology, cellular agriculture, and conservation, and this method has the potential to be expanded to species not yet tested, as well as to other organs.

4.
Heliyon ; 10(15): e35387, 2024 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-39170270

RESUMEN

As one of the key components of electric vehicles, the enhancement of the performance of the power battery is closely intertwined with an efficient Battery Thermal Management System (BTMS). In the realm of BTMS, Flat Heat Pipes (FHP) have garnered considerable attention due to their lightweight structure and excellent thermal conductivity. Thus, a BTMS configuration scheme based on FHP is proposed in this study. Utilizing orthogonal design and fuzzy grey relational analysis as the evaluation methods, coupled with numerical simulations, an investigation into the influence of four structural parameters of the novel biomimetic fins (namely, the diameter, height, spacing of protrusions, and height of cooling fins) on the temperature distribution of the battery pack is conducted. The research findings indicate that to maintain the battery within an optimal operational temperature range, the optimal dimensional parameters should be controlled at 17.5 mm, 4 mm, 13 mm, and 90 mm, respectively. Subsequent sensitivity analysis reveals that the height of the protrusions exhibits the most significant influence on the maximum temperature of the module, whereas the height of the cooling fins exerts a considerable impact on the consistency of the module temperature. The optimized maximum temperature is determined to be 36.52 °C, with a temperature difference of 2.65 °C.

5.
Biology (Basel) ; 13(7)2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-39056673

RESUMEN

Teleosts are the most prolific vertebrates, occupying the vast majority of aquatic environments, and their pectoral fins have undergone remarkable physiological transformations throughout their evolution. Studying early teleost fishes, such as those belonging to the Osteoglossiformes order, could offer crucial insights into the adaptive evolution of pectoral fins within this group. In this study, we have assembled a chromosomal-level genome for the Clown featherback (Chitala ornata), achieving the highest quality genome assembly for Osteoglossiformes to date, with a contig N50 of 32.78 Mb and a scaffold N50 of 40.73 Mb. By combining phylogenetic analysis, we determined that the Clown featherback diverged approximately 202 to 203 million years ago (Ma), aligning with continental separation events. Our analysis revealed the intriguing discovery that a unique deletion of regulatory elements is adjacent to the Gli3 gene, specifically in teleosts. This deletion might be tied to the specialized adaptation of their pectoral fins. Furthermore, our findings indicate that specific contractions and expansions of transposable elements (TEs) in teleosts, including the Clown featherback, could be connected to their adaptive evolution. In essence, this study not only provides a high-quality genomic resource for Osteoglossiformes but also sheds light on the evolutionary trajectory of early teleosts.

6.
Interface Focus ; 14(3): 20230072, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-39081621

RESUMEN

Morphing materials are typically either very compliant to achieve large shape changes or very stiff but with small shape changes that require large actuation forces. Interestingly, fish fins overcome these limitations: fish fins do not contain muscles, yet they can change the shape of their fins with high precision and speed while producing large hydrodynamic forces without collapsing. Here, we present a 'stiff' morphing beam inspired from the individual rays in natural fish fins. These synthetic rays are made of acrylic (PMMA) outer beams ('hemitrichs') connected with rubber ligaments which are 3-4 orders of magnitude more compliant. Combinations of experiments and models of these synthetic rays show strong nonlinear geometrical effects: the ligaments are 'mechanically invisible' at small deformations, but they delay buckling and improve the stability of the ray at large deformations. We use the models and experiments to explore designs with variable ligament densities, and we generate design guidelines for optimum morphing shape (captured using the first moment of curvature), that capture the trade-offs between morphing compliance (ease of morphing the structure) and flexural stiffness. The design guidelines proposed here can help the development of stiff morphing bioinspired structures for a variety of applications in aerospace, biomedicine or robotics.

7.
J Anim Ecol ; 93(8): 1135-1146, 2024 08.
Artículo en Inglés | MEDLINE | ID: mdl-38898692

RESUMEN

Fish fins are remarkable devices of propulsion. Fin morphology is intimately linked to locomotor performance, and hence to behaviours that influence fitness, such as foraging and predator avoidance. This foreshadows a connection between fin morphology and variation in predation risk. Yet, whether prey can adjust fin morphology according to changes in perceived risk within their lifetime (a.k.a. predator-induced plasticity) remains elusive. Here, we quantify the structural size of five focal fins in crucian carp (Carassius carassius) following controlled manipulations to perceived predation risk (presence/absence of pike Esox lucius). We also assess if crucian carp respond to increased predation risk by shifts in dorsal fin colouration, and test for differences in how fish actively use their dorsal fins by quantifying the area of the fin displayed in behavioural trials. We find that crucian carp show phenotypic plasticity with regards to fin size as predator-exposed fish consistently have larger fins. Individuals exposed to perceived predation risk also increased dorsal fin darkness and actively displayed a larger area of the fin to potential predators. Our results thus provide compelling evidence for predator-induced fin enlargement, which should result in enhanced escape swimming performance. Moreover, fin-size plasticity may evolve synergistically with fin colouration and display behaviour, and we suggest that the adaptive value of this synergy is to enhance the silhouette of deep-bodied and hard-to-capture prey to deter gape-limited predators prior to attack. Together, our results provide new perspectives on the role of predation risk in development and evolution of fins.


Asunto(s)
Aletas de Animales , Carpas , Esocidae , Conducta Predatoria , Animales , Aletas de Animales/fisiología , Aletas de Animales/anatomía & histología , Carpas/fisiología , Carpas/anatomía & histología , Esocidae/fisiología , Esocidae/anatomía & histología , Oscuridad , Natación
8.
Proc Natl Acad Sci U S A ; 121(25): e2403809121, 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38861596

RESUMEN

The dorsal and anal fins can vary widely in position and length along the anterior-posterior axis in teleost fishes. However, the molecular mechanisms underlying the diversification of these fins remain unknown. Here, we used genetic approaches in zebrafish and medaka, in which the relative positions of the dorsal and anal fins are opposite, to demonstrate the crucial role of hox genes in the patterning of the teleost posterior body, including the dorsal and anal fins. By the CRISPR-Cas9-induced frameshift mutations and positional cloning of spontaneous dorsalfinless medaka, we show that various hox mutants exhibit the absence of dorsal or anal fins, or a stepwise posterior extension of these fins, with vertebral abnormalities. Our results indicate that multiple hox genes, primarily from hoxc-related clusters, encompass the regions responsible for the dorsal and anal fin formation along the anterior-posterior axis. These results further suggest that shifts in the anterior boundaries of hox expression which vary among fish species, lead to diversification in the position and size of the dorsal and anal fins, similar to how modulations in Hox expression can alter the number of anatomically distinct vertebrae in tetrapods. Furthermore, we show that hox genes responsible for dorsal fin formation are different between zebrafish and medaka. Our results suggest that a novel mechanism has occurred during teleost evolution, in which the gene network responsible for fin formation might have switched to the regulation downstream of other hox genes, leading to the remarkable diversity in the dorsal fin position.


Asunto(s)
Aletas de Animales , Genes Homeobox , Proteínas de Homeodominio , Oryzias , Pez Cebra , Animales , Oryzias/genética , Pez Cebra/genética , Genes Homeobox/genética , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Regulación del Desarrollo de la Expresión Génica , Tipificación del Cuerpo/genética , Proteínas de Peces/genética , Proteínas de Peces/metabolismo
9.
J Morphol ; 285(6): e21744, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38850202

RESUMEN

Leptocharias smithii has been poorly explored in anatomical terms. This species bears a mosaic of morphological characters and is considered to represent an intermediate condition between other carcharhiniform clades. In the present paper, the anatomy of the appendicular skeleton of the species is thoroughly investigated and compared with other representatives of the order Carcharhiniformes. Leptocharias bears exclusive characteristics, such as the visible separation of the pro- and mesopterygia but it also has an aplesodic pectoral fin, a condition shared with carcharhiniforms placed at the base of the phylogenetic tree and at the same time a chevron-shaped coracoid bar, a condition characteristic of charcharhiniforms placed at the apex of the phylogenetic tree. Additionally, in an attempt to understand the evolution of its appendicular skeleton and of other carcharhiniforms, 20 characters of the paired fins and girdles are explored and discussed in light of two recent phylogenetic hypotheses. Most of these characters were not previously explored and support not only the monophyly of Carcharhiniformes, such as the mesopterygium overlapping the metapterygium in ventral view, but also the monophyly of the less inclusive clade Hemigaleidae + (Galeocerdonidae + (Carcharhinidae+Sphyrnidae)), such as the morphology and arrangement of the distal radials, which are pointed and spaced.


Asunto(s)
Filogenia , Tiburones , Animales , Tiburones/anatomía & histología , Tiburones/clasificación , Aletas de Animales/anatomía & histología , Masculino , Femenino , Evolución Biológica
10.
Bioinspir Biomim ; 19(4)2024 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-38722377

RESUMEN

State-of-the-art morphing materials are either very compliant to achieve large shape changes (flexible metamaterials, compliant mechanisms, hydrogels), or very stiff but with infinitesimal changes in shape that require large actuation forces (metallic or composite panels with piezoelectric actuation). Morphing efficiency and structural stiffness are therefore mutually exclusive properties in current engineering morphing materials, which limits the range of their applicability. Interestingly, natural fish fins do not contain muscles, yet they can morph to large amplitudes with minimal muscular actuation forces from the base while producing large hydrodynamic forces without collapsing. This sophisticated mechanical response has already inspired several synthetic fin rays with various applications. However, most 'synthetic' fin rays have only considered uniform properties and structures along the rays while in natural fin rays, gradients of properties are prominent. In this study, we designed, modeled, fabricated and tested synthetic fin rays with bioinspired gradients of properties. The rays were composed of two hemitrichs made of a stiff polymer, joined by a much softer core region made of elastomeric ligaments. Using combinations of experiments and nonlinear mechanical models, we found that gradients in both the core region and hemitrichs can increase the morphing and stiffening response of individual rays. Introducing a positive gradient of ligament density in the core region (the density of ligament increases towards the tip of the ray) decreased the actuation force required for morphing and increased overall flexural stiffness. Introducing a gradient of property in the hemitrichs, by tapering them, produced morphing deformations that were distributed over long distances along the length of the ray. These new insights on the interplay between material architecture and properties in nonlinear regimes of deformation can improve the designs of morphing structures that combine high morphing efficiency and high stiffness from external forces, with potential applications in aerospace or robotics.


Asunto(s)
Aletas de Animales , Materiales Biomiméticos , Animales , Aletas de Animales/fisiología , Aletas de Animales/anatomía & histología , Fenómenos Biomecánicos , Biomimética/métodos , Peces/fisiología , Peces/anatomía & histología
11.
Paediatr Child Health ; 29(2): 104-121, 2024 May.
Artículo en Inglés, Inglés | MEDLINE | ID: mdl-38586491

RESUMEN

L'intérêt envers l'utilisation des produits du cannabis à des fins médicales chez les enfants de moins de 18 ans augmente. De nombreux produits du cannabis à des fins médicales contiennent du cannabidiol, du delta-9-tétrahydrocannabinol ou ces deux produits. Malgré les nombreuses prétentions thérapeutiques, peu d'études rigoureuses guident la posologie, l'innocuité et l'efficacité du cannabis à des fins médicales en pédiatrie clinique. Le présent document de principes passe en revue les données probantes à jour et expose les recommandations sur l'utilisation du cannabis à des fins médicales chez les enfants. Les rapports à plus long terme (deux ans) souscrivent à la tolérabilité et à l'efficacité soutenues d'un traitement au cannabidiol chez les patients ayant le syndrome de Lennox-Gastaut ou le syndrome de Dravet. Les extraits de cannabis enrichis de cannabidiol qui renferment de petites quantités de delta-9-tétrahydrocannabinol ont été évalués auprès d'un petit nombre de patients d'âge pédiatrique, et d'autres recherches devront être réalisées pour éclairer les guides de pratique clinique. Étant donné l'utilisation répandue du cannabis à des fins médicales au Canada, les pédiatres devraient être prêts à participer à des échanges ouverts et continus avec les familles au sujet de ses avantages potentiels et de ses risques, ainsi qu'à préparer des plans individuels en vue d'en surveiller l'efficacité, de réduire les méfaits et de limiter les interactions médicamenteuses.

12.
Heliyon ; 10(7): e28146, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38590902

RESUMEN

This study numerically investigated the improvement of heat transmission to phase change material (PCM) paraffin wax in a triangular cell with and without fins. The enthalpy-porosity combination was quantitatively evaluated using the ANSYS/FLUENT 20 program. Materials with the phase shifts of paraffin wax were used in this study (RT42). According to the study findings, fins significantly accelerate the melting process and decrease the time required to finish it. The time difference between melting with and without fins is 125%. Moreover, the inclusion of v-shaped fins contributed to a 200% reduction in the melting process time. Thus, the use of v-shaped fins facilitates faster heat transfer to and from the applications wherein the phase change materials are used.

13.
Heliyon ; 10(7): e28323, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38560223

RESUMEN

This research aims to determine the impact of mass flow rate and inflow temperature on the utility and effectiveness of solar thermal systems using fins with air in various applications in Bangladesh. This study examines a three-dimensional (3D) photovoltaic thermal (PVT) system where we analyze the behavior of a hybrid system with six aluminum sheets (1 mm thick fin as a heat exchange material) inside the heat exchanger where the air takes the direction to pass in waveform through the channels (made of aluminum) using fins. The top side of the fins is bent and affixed to the bottom of the floor of the PV panel to allow heat transfer utilizing the conduction-based method. This study selects inlet fluid mass flow rate and inflow temperature between (0.015-0.535 kg/s), and (10-40 °C) respectively, while comparing the result with experimental/numerical published data based on Bangladesh's weather conditions and applies the finite element method (FEM) to solve heat transfer equations. A brief analysis of the association among Reynolds number with pressure drop and fanning friction factor is included in this paper. Our model can be mounted on building rooftops or open fields where air velocity will be controlled mechanically; thus, it has many applications. This model can be implemented within an agricultural photovoltaic (APV) system, domestic functions, dry agricultural products, and provide heat for greenhouses. The result indicates that 302-514 W thermal energy has been produced for 0.015-0.535 kg/s. For growing inflow temperature, despite the reduction in electrical efficiency, the value of adding electrical and thermal efficiency (overall efficiency) comes with elevation. A 5 °C increase in inflow temperature leads to an overall efficiency increase of 0.33%. This study's findings can help researchers better comprehend air's properties as a heat exchanger in a developed design, and they can be applied to government and commercial projects.

14.
J Funct Morphol Kinesiol ; 9(2)2024 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-38651437

RESUMEN

Coastal environments present dynamic challenges necessitating rapid and efficient responses during aquatic emergencies. Lifeguards, as pivotal links in the intervention chain, rely on various tools, with rescue time being paramount. The choice of fins, specifically long versus short ones, plays a critical role in optimizing lifeguard performance during rescues. This randomized cross-over study explores the impact of flipper size on ocean rescues, employing a sample of 14 lifeguards. Long fins (LFs) and short fins (SFs) were compared in terms of rescue time (RT) and physiological load (PL). Tests included ocean rescues without fins (R), with LF (R-LF), and with SF (R-SF). Variables recorded encompassed swim approach time, tow-in time, overall rescue time, perceived exertion rates (RPEs), and post-rescue lactate concentration. Long fins demonstrated superior performance in swim approach and tow-in times compared to both short fins and no fins (p < 0.001). Overall rescue time favored long fins significantly (p < 0.001), indicating their efficiency in practical ocean rescue scenarios. Physiologically, long fins induced lower perceived exertion in arms (p = 0.033) compared to short fins. Lactate concentrations post-rescue revealed no significant differences (p > 0.05). This study demonstrates that long fins significantly improve lifeguard performance during ocean rescues, reducing rescue times and alleviating arm fatigue.

15.
Biomimetics (Basel) ; 9(3)2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38534841

RESUMEN

Fish swimming has attracted attention as a locomotion system with excellent propulsive efficiency. They swim by moving their body, fins, and other organs simultaneously, which developed during evolution. Among their many organs, the pectoral fin plays a crucial role in swimming, such as forward-backward movement and change of direction. In order to investigate the hydrodynamic interaction between pectoral fins and fish bodies, we examined the asymmetric flapping motion of the pectoral fin concerning the body axis and investigated the effect of the pectoral fin on the propulsive performance of the body of a small swimming object by numerical simulation. In this study, the amplitude ratio, frequency ratio, and phase of the body and pectoral fin varied. Therefore, although propulsive performance increased in tandem with the frequency ratio, the amplitude ratio change had negatively affected the propulsive performance. The results revealed that the propulsive performance of the fish was high even in low-frequency ratios when the phase difference was varied. The highest propulsion efficiency increased by a factor of about 3.7 compared to the phase difference condition of 0.

16.
Artículo en Inglés | MEDLINE | ID: mdl-37971583

RESUMEN

Effective utilization and conservation of freshwater is a global concern due to the rapid population growth and industrial usage. To address this challenge, various approaches have been developed and implemented to convert brackish water into freshwater and meet the global water demand. This study introduces hexagram-shaped aluminum fins attached to a powder-coated basin to improve the freshwater production rate of stepped solar still. The experiment involved testing the modified stepped solar still (MSSS) equipped with hexagram fins and the conventional stepped solar still (CSSS) without hexagram fins during summer days at the Sathyamangalam location (11.49° N, 77.27° E). A mathematical model was used to analyze the performance of the solar stills, and the simulation results were validated by comparing CSSS and MSSS in terms of their freshwater production. The results indicate that the productivity of CSSS increased by 40% using hexagram fins, and the MSSS with hexagram fins produced a maximum of 4.45 l/m2 of fresh water daily. The annual performance of MSSS and CSSS in the experimental location reveals a 12.6% reduction in the payback period of the solar still due to the presence of fins. The study recommends using fins in solar stills in hot climates for efficient and cost-effective water desalination applications to achieve sustainable development objectives while reducing carbon emissions.

17.
Biomimetics (Basel) ; 8(7)2023 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-37999163

RESUMEN

This article aims to numerically study the hydrodynamic performance of the bionic dolphin equipped with a pair of rigid pectoral fins. We use dynamic-grid technology and user-defined functions to simulate a novel butterfly-mode flapping propulsion of the fins. This pattern of propulsion is composed of three angular degrees of freedom including the pitch angle ϕp, the azimuth angle ϕa and the roll angle ϕr, which can be divided into four stages for analysis within a single cycle. The stroke of one single pectoral fin can be approximated as an ellipse trajectory, where the amplitudes of ϕa and ϕp, respectively, determine the major and minor axes of the ellipse. The fluid dynamics involved in the specific butterfly pattern is mathematically formulated, and numerical simulation is conducted to investigate the propulsion quantitatively. The results show that the dolphin with a higher water striking frequency f can acquire higher propulsion speed and efficiency. Furthermore, the shape of the ellipse trajectory under different conditions could also have different propulsion effects. The periodic generation and disappearance of vortex structures in the butterfly flapping mode show the evolution process of fluid flow around a pair of pectoral fins, which reveals the influence of motion parameters on fluid dynamics under different working conditions.

18.
Heliyon ; 9(11): e21236, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38027558

RESUMEN

The solar receiver is a vital component of concentrated solar collectors that absorbs solar radiation and converts it into heat. One of the challenges the research community faces is minimizing heat loss from the receiver at higher temperatures to maximize the thermal performance of parabolic dish collectors and achieve the system's cost-effectiveness. Cavity receivers have a complex design that makes them more challenging to manufacture and entails higher costs for improved thermal performance. Implementing innovative receiver designs is essential to maximize the absorption of solar radiation and minimize heat losses. In this experimental study, a cost-effective solar receiver was fabricated with fins to study heat transfer. The solar receiver is examined using water as heat transfer fluid with three flow rates of 0.097 kg/s, 0.125 kg/s, and 0.152 kg/s. The residence time of water is increased by adopting integrated fin receiver designs. The provision of fins in the solar receiver enhances heat transfer by increasing the turbulence in the fluid flow and results in higher thermal efficiency. The average energy and exergy efficiencies are 67.81 % and 8.93 %, respectively, with a 0.152 kg/s flow rate. At the highest water flow rate (0.152 kg/s) considered in this study, a lesser heat loss of about 3776.2 W occurred due to the effective heat transfer. The cost metrics, like levelized cost of electricity, net present value, and the payback period, are about 0.21 $/kWh, 923 $, and 3.38 years, respectively, at 0.152 kg/s flow rate. The proposed solar receiver produces optimal thermo-economic performance and lower initial investment for steam generation than other receiver designs. The current experimental study's findings could benefit the entire solar industry by presenting an effective solar receiver design for solar collectors.

19.
Biomimetics (Basel) ; 8(5)2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37754158

RESUMEN

Bionic robotic fish have advantages over traditional underwater propulsion. Most of the existing studies have been conducted with only one type of fish as a bionic object, but a single propulsion mode may not be able to achieve the different needs of underwater operations. In this paper, we designed a pneumatic variable-configuration soft bionic fish and completed the overall structure design. It was built with a cownose ray as the main-configuration bionic object and a Caranx melampygus as the secondary-configuration bionic object. The base structure, actuators, and variable-configuration modules of the robot were made using flexible materials. After completing the design of the structure and control system of the robot, the prototype was manufactured and an underwater test was completed. The tests results indicated that the robot fish could achieve underwater linear propulsion and turning movements in both configurations. The maximum propulsion speed of the main configuration was 38.24 mm/s and the turning angle speed was 5.6°/s, and the maximum propulsion speed of its secondary configuration was 43.05 mm/s and the turning angle speed was 30°/s. The feasibility of the machine fish structure and control scheme were verified.

20.
Rio de Janeiro; s.n; 20.set.2023. 56 p. tab, graf, mapas.
Tesis en Portugués | LILACS, SES-RJ | ID: biblio-1566125

RESUMEN

Esta dissertação tem como objeto de estudo a participação das Organizações Sociais no Sistema Único de Saúde (SUS), a partir do estudo de caso do Hospital Estadual da Mulher Heloneida Studart (HEMHS). Os objetivos gerais são contribuir para o entendimento da participação das Organizações Sociais no âmbito do SUS, com base na análise dos contratos de gestão em unidade de saúde pertencente à Secretaria de Estado de Saúde do Rio de Janeiro (SES-RJ) e na avaliação do desempenho da produção hospitalar dessa unidade no período de 2012 a 2022, e cooperar para o aperfeiçoamento dos processos de contratualização das unidades de saúde no âmbito da SES-RJ. São objetivos específicos: identificar e descrever os contratos de gestão do HEMHS no período de 2012 a 2022, comparar a evolução dos valores pagos nos contratos de gestão para operacionalização do HEMHS de 2012 a 2022, analisar a evolução da produção do HEMHS de 2012 a 2022 e o atingimento das metas pactuadas relacionadas aos indicadores quantitativos disponíveis nos contratos de gestão e sugerir ajustes nos contratos de gestão e nas formas de monitoramento e avaliação da SES-RJ, com base nas lições aprendidas. Para alcançar os objetivos propostos, foram utilizadas pesquisas documentais e bibliográficas. Na pesquisa bibliográfica, buscaram-se conhecimento e aprofundamento dos diferentes modelos de gestão dos serviços de saúde no Brasil, e mais especificamente no Estado do Rio de Janeiro, com o advento das Organizações Sociais no SUS. A pesquisa documental teve como fonte de dados os instrumentos normativos sobre Organizações Sociais no Brasil e no Estado do Rio de Janeiro, como leis, decretos e portarias, além dos contratos de gestão e relatórios de prestações de contas disponibilizados no sítio da SES-RJ. Os resultados da pesquisa demonstraram que, ao longo do período estudado, os recursos firmados em contratos tiveram pouca variação, bem como os recursos efetivamente pagos. As metas de produção obtidas demonstraram que alguns procedimentos tiveram resultados superiores ao contratado e outros procedimentos, resultados inferiores. Apesar da demanda pelos serviços no período de 2012 a 2022, os procedimentos de vídeo-histeroscopia, mamografia e mamografia guiada por ultrassonografia jamais alcançaram os resultados pactuados. A pesquisa também não conseguiu estabelecer uma relação direta entre o repasse de recurso e o alcance das metas contratuais. (AU)


This dissertation aims to study the participation of Social Organizations in the Unified Health System (SUS), based on the case study of the Heloneida Studart Women's State Hospital (HEMHS). The general objectives are to contribute to the understanding of the participation of Social Organizations within the scope of the SUS, based on the analysis of management contracts in a health unit belonging to the State Department of Health of Rio de Janeiro (SES-RJ) and the evaluation of the performance of this unit's hospital production from 2012 to 2022, and cooperate to improve the contracting processes of health units within the scope of SES-RJ. Specific objectives are: identify and describe HEMHS management contracts from 2012 to 2022, compare the evolution of amounts paid in management contracts for the operationalization of HEMHS from 2012 to 2022, analyze the evolution of HEMHS production from 2012 to 2022 and the achievement of agreed goals related to the quantitative indicators available in the management contracts and suggesting adjustments to the management contracts and the forms of monitoring and evaluation of SES-RJ, based on the lessons learned. To achieve the proposed objectives, documentary and bibliographical research was used. In the bibliographical research, we sought knowledge and deepening of the different management models of health services in Brazil, and more specifically in the State of Rio de Janeiro, with the advent of Social Organizations in the SUS. The documentary research had as its data source the normative instruments on Social Organizations in Brazil and the State of Rio de Janeiro, such as laws, decrees and ordinances, in addition to management contracts and accountability reports available on the SES-RJ website. The research results demonstrated that, throughout the period studied, the resources signed in contracts had little variation, as well as the resources actually paid. The production targets obtained demonstrated that some procedures had results superior to those contracted and other procedures had inferior results. Despite the demand for services from 2012 to 2022, video hysteroscopy, mammography and ultrasound-guided mammography procedures never achieved the agreed results. The research was also unable to establish a direct relationship between the transfer of resources and the achievement of contractual goals. (AU)

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