This study was funded by the U.S. Department of Energy (DOE) Water Power Technologies Office. The laboratory studies were conducted at Pacific Northwest National Laboratory, which is operated by Battelle for the DOE under Contract DE-AC05-76RL01830.

1. Acid/base encapsulation
<ol>
	<li>Mix a 1:2 ratio by the weight of H2C2O4 (oxalic acid) and NaHCO3 (sodium bicarbonate) in a mixing cup (see Table of Materials). If the acid-base powder mix is crystallized, grind it down using a mortar and pestle (Figure 1A).</li>
	<li>Retrieve the size 3 vegetable-based capsules and the semi-automatic capsule filling machine to begin the process (see Table of Materials).</li>
	<li>Place the cap sheet flat on a clean, dry surface. Align the encapsulation sheet on top of the cap sheet using the black pegs to fix it correctly in place (Figure 1B).</li>
	<li>Separate the capsule tops and bottoms, unless using pre-separated capsules. The size #3 vegetable capsules, when closed, have overall dimensions of 15.9 mm in length, 5.57 mm in outer diameter (OD), 0.30 mL in volume, and weigh 47 mg.</li>
	<li>Pour capsule tops into the encapsulation sheet (Figure 1C). Gently shake the tops into the holes with a circular motion. While doing this, cover the gap in the wall of the encapsulation sheet with one hand or a powder spreader to avoid spilling the tops (Figure 1D).
	<ol>
		<li>Once the holes are filled, pour the excess capsule tops into a clean cup (Figure 1E). Identify any upside-down capsule tops and turn them over (Figure 1F). Ensure that all capsule tops are facing the correct direction in the cap sheet. It is important to ensure proper orientation, as incorrect alignment may result in capsule tops not properly joining with the capsule bottoms.</li>
	</ol>
	</li>
	<li>Remove the encapsulation sheet and set aside the filled cap sheet.</li>
	<li>Take out the body or &#34;bottom&#34; sheet. Place it on a clean, dry, flat surface. Fix the encapsulation sheet to the bottom sheet, ensuring proper alignment by utilizing the black pegs to position it correctly in place.</li>
	<li>Pour capsule bottoms into the encapsulation sheet and shake as before in a circular motion to fill the holes. Pour off excess capsule bottoms. Identify any upside-down capsule bottoms and turn them over.</li>
	<li>Remove the encapsulation sheet from the bottom sheet and set it aside.</li>
	<li>Pour the acid/base powder mixture onto the filled bottom sheet (Figure 1G). Use a plastic spreader to fill the capsule bottoms with the powder (Figure 1H). Check that all the capsule bottoms are filled (Figure 1I). Remove any unused acid/base powder.</li>
	<li>Place the cap sheet on a flat surface and position the middle sheet on top, aligning it with the black pegs to ensure a correct fit. Ensure to line up all the capsule tops with the corresponding holes in the middle sheet.</li>
	<li>Invert the cap sheet with the affixed middle sheet and align it with the filled bottom sheet (Figure 1J).</li>
	<li>Gently press down on the cap sheet equally on all sides to join the tops and bottoms, fitting both sides of the capsule together (Figure 1K).</li>
	<li>Remove the cap sheet and middle sheet from the bottom sheet. At this point, the capsule bottoms and tops should be properly joined together.
	<ol>
		<li>Verify that each capsule top and bottom are fitted tightly; if not, manually press the capsule top and bottom together to create a tight fit. Remove the filled capsules and place them in an airtight, sealable container (Figure 1L). 
		NOTE: For safe handling, it is essential for users to wear personal protective equipment (PPE) and face protection. Adequate ventilation should be ensured, and precautions should be taken to avoid ingestion, inhalation, and contact with the substance on the skin, eyes, or clothing. Additionally, it is important to prevent the generation of dust. For detailed information regarding safety, please refer to the safety data sheet (SDS) for oxalic acid and sodium bicarbonate. To maintain the integrity of the acid/base capsules, it is advised to store them away from direct sunlight and high humidity. Store the unused capsules in a sealed, airtight container. As long as the capsules are kept dry and free from moisture, they can be used effectively to ensure optimal functionality.</li>
	</ol>
	</li>
</ol>
2. Silicone stopper manufacture
<ol>
	<li>Using a fused deposition modeling (FDM) 3D printer (see Table of Materials), print a mold plate using the STL file provided in Supplementary File 1.</li>
	<li>Place a clear packing tape on the bottom side of the mold plate so that each opening is sealed (Figure 2A).</li>
	<li>Mix a 1:1 ratio by weight (e.g., 50 g each of Part A and Part B) of the commercially available silicone mold material into a mixing cup (see Table of Materials). Using a disposable spoon, thoroughly mix the chemical compound for approximately 5 min, or until it has become uniform.</li>
	<li>Place the mold plate with the packing tape over a piece of paper. The paper will catch any potential silicone spill from the mold plate.</li>
	<li>Begin pouring the silicone mixture into each stopper hole, ensuring they are all filled (Figure 2B). Use a rubber squeegee to spread the silicone into each stopper hole (Figure 2C). Remove the leftover silicone mixture from the surface of the mold plate.</li>
	<li>Let the rubber stoppers dry for 4 h. After making sure the stoppers have fully cured (e.g., the silicone mixture has completely dried and hardened), remove the tape from the back of the mold plate (Figure 2D), and then begin pulling the stoppers out of the mold (Figure 2E).</li>
	<li>Remove any excess silicone attached to the stoppers (Figure 2F).</li>
</ol>
3. Balloon tag assembly
<ol>
	<li>Carefully insert the piercing tool (e.g., straight dental pick) into the silicone stopper (Figure 3A) (see Table of Materials). Insert the piercing tool into a 15 G syringe needle and then remove the piercing tool from the silicone stopper, leaving only the 15 G needle inside (Figure 3B). The piercing tool will create a slit inside the silicone stopper without cutting or removing any material.</li>
	<li>Cut a piece of 50 lb. fishing line (see Table of Materials) to a length of 150 mm. Insert the fishing line through the 15 G syringe needle and into the silicone stopper (Figure 3C).
	<ol>
		<li>While carefully holding the stopper and the fishing line together, remove the 15 G syringe needle from the stopper&#39;s body, leaving the fishing line inside the stopper (Figure 3D). Ensure the fishing line lengths are even on both sides of the stopper.</li>
	</ol>
	</li>
	<li>Insert two acid/base-powder-filled capsules into a latex balloon (Figure 3E) (see Table of Materials). Expand the balloon opening using the rubber-band expansion tool (i.e., castration band pliers) and then carefully insert one silicone stopper into the balloon opening (Figure 3F), leaving the fishing line&#39;s two ends outside the balloon.</li>
	<li>Place two O-rings (1.6 mm wide, 8.1 mm ID, see Table of Materials) onto the rubber-band expansion tool and expand them. Insert the neck of the latex balloon through the two expanded O-rings (Figure 3G). Carefully pull the two O-rings away from the rubber-band expansion tool, leaving them tightly wrapped around the balloon&#39;s neck, centered on the stopper (Figure 3H).</li>
</ol>
4. Balloon tag attachment to Sensor Fish caps
<ol>
	<li>Put one end of the fishing line through one of the small holes in the Sensor Fish cap (see Table of Materials) and bring it through the large hole in the center of the cap (Figure 4A).</li>
	<li>Tie the two ends of the fishing line together, leaving about 13 to 26 mm between the top of the cap and the base of the balloon. Use four overhand knots on top of each other when tying the fishing line.</li>
	<li>Leave the extra fishing line attached, as cutting it too close to a knot could potentially cause the knot to come undone (Figure 4B).</li>
	<li>Test the knot by gripping the fishing line on each side of the knot with the fingers and pulling as hard as possible. Be cautious not to pull too close to the balloon, as it could unintentionally tear the fishing line through the rubber stopper.</li>
</ol>

Optimizing Balloon Tag Assembly to Recover Sensor Fish and Live Fish

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D., Mueller, R., Titzler, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+situ+characterization+of+the+biological+performance+of+a+Francis+turbine+retrofitted+with+a+modular+guide+vane.">In situ characterization of the biological performance of a Francis turbine retrofitted with a modular guide vane.</a> Applied Energy. 276, 115492 (2020).</li><li>&#268;ada, G. l. e. n. n. . F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+development+of+advanced+hydroelectric+turbines+to+improve+fish+passage+survival.">The development of advanced hydroelectric turbines to improve fish passage survival.</a> Fisheries. 26, 14-23 (2001).</li><li>Tuononen, E. I., Cooke, S. J., Timusk, E. R., Smokorowski, K. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extent+of+injury+and+mortality+arising+from+entrainment+of+fish+through+a+Very+Low+Head+hydropower+turbine+in+central+Ontario,+Canada.">Extent of injury and mortality arising from entrainment of fish through a Very Low Head hydropower turbine in central Ontario, Canada.</a> Hydrobiologia. 849, 407-420 (2020).</li><li>Deng, Z., Carlson, T. J., Duncan, J. P., Richmond, M. C., Dauble, D. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+an+autonomous+sensor+to+evaluate+the+biological+performance+of+the+advanced+turbine+at+Wanapum+Dam.">Use of an autonomous sensor to evaluate the biological performance of the advanced turbine at Wanapum Dam.</a> Journal of Renewable and Sustainable Energy. 2, 053104 (2010).</li><li>Martinez, J. 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P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Physical+and+ecological+evaluation+of+a+fish-friendly+surface+spillway.">Physical and ecological evaluation of a fish-friendly surface spillway.</a> Ecological Engineering. 110, 107-116 (2018).</li><li>Trumbo, B. r. a. d. l. y. . A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improving+hydroturbine+pressures+to+enhance+salmon+passage+survival+and+recovery.">Improving hydroturbine pressures to enhance salmon passage survival and recovery.</a> Reviews in fish biology and fisheries. 24, 955-965 (2014).</li><li>Pohanish, R. 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The authors have no conflicts of interest.

This study concluded that three-capsule balloon tags injected with 5 mL of water at 18.3 &#176;C had a slower start inflation time and consistently larger volume compared to two-capsule and four-capsule balloon tags. When the balloon tags were injected with water at 12.7 &#176;C, the average volume was smaller, and the inflation time was longer. The three-capsule begins deflating first, followed by the four-capsule, and lastly the two-capsule. The inflation and deflation periods associated with each water temperature can...

Hydropower is a significant renewable energy resource worldwide. In the United States, hydropower contributes an estimated 38% or 274 TWh of electricity generated from renewable sources1 and has the potential to add approximately 460 TWh per year2. However, as hydropower development increases, concerns about fish injury and mortality during hydraulic passage have become paramount3. Various mechanisms contribute to fish injuries during passage, including rapid decompression (barotrauma), shear stress, turbulence, strikes, cavitation, and grinding4. Although these injury mechanisms may not have an immediate impact on the overall condition of the fish, they can render them more vulnerable to diseases, fungal infections, parasites, and predation5. Additionally, direct physical injuries resulting from collisions with turbines or other hydraulic structures can lead to significant mortality, emphasizing the importance of mitigating these risks in hydropower development.
One of the most common methods for evaluating fish passage conditions is releasing Sensor Fish and live fish through hydraulic structures6,7. The Sensor Fish is an autonomous device designed to study the physical conditions that fish experience during passage through hydraulic structures, including turbines, spillways, and dam bypass alternatives8,9. Equipped with a 3D accelerometer, 3D gyroscope, temperature sensor, and pressure sensor9, the Sensor Fish provides valuable data on fish passage conditions.
Balloon tags, which are self-inflating balloons attached externally to Sensor Fish and live fish, assist in their recovery after passing through hydraulic structures. The balloon tags consist of dissolvable capsules filled with gas-generating chemicals (e.g., oxalic acid and sodium bicarbonate), a silicone stopper, and a fishing line. Prior to deployment, water is injected through the silicone stopper into the balloon. The water dissolves the vegetable-based capsules, triggering a chemical reaction that produces gas&#160;inflating the balloon. In this neutralization reaction, sodium bicarbonate, a weak base, and oxalic acid, a weak acid, react to form carbon dioxide, water, and sodium oxalate10. The chemical reaction is provided below:
2NaHCO3+ H2C2O4 &#8594; 2CO2 + 2H2O + Na2C2O4
The inflated balloon increases the buoyancy of the Sensor Fish and live fish, enabling them to float on&#160;the water surface for easier recovery.
The number of balloon tags required to achieve flotation and facilitate the retrieval of a sample (e.g., Sensor Fish or live fish) may vary based on the volume and mass characteristics of the sample. The duration of balloon tag inflation can be adjusted by injecting water at different temperatures. Colder water will increase the inflation time, while warmer water will decrease it. Balloon tags have been successfully employed in various locations, including the Farmers Screen, a unique horizontal, flat-plate fish and debris screen structure in Hood River, Oregon11, and a Francis turbine at Nam Ngum Dam in the Lao People&#39;s Democratic Republic12. Another commercially available balloon tag example is the Hi-Z Turb&#39;N Tag13,14. The Hi-Z Turb&#39;N Tag allows inflation time to be adjusted between 2 min and 60 min, depending on the injected water temperature13. This technology has been used in fish studies at many field sites, including studies involving Chinook salmon smolts released at Rocky Reach Dam on the Columbia River and juvenile American shad at Hadley Falls Dam on the Connecticut River15,16. Both technologies utilize acid-base&#160;chemical reactions to inflate the balloon tags for recovery.
This method offers cost-effectiveness and simplicity in manufacturing, with an estimated material cost of only $0.50 per balloon. As described here, the manufacturing process is easy to follow, making balloon tag production accessible to anyone.

<table><tbody><tr><td>3D Printed Silicone Stopper Plate</td><td>NA</td><td>NA</td><td></td></tr><tr><td>ARC800 Sensor Fish</td><td>ATS</td><td>NA</td><td></td></tr><tr><td>FDM 3D printer</td><td>NA</td><td>NA</td><td></td></tr><tr><td>Manual Capsule Filler Machine CN-400CL (Size #3)</td><td>Capsulcn</td><td>NA</td><td></td></tr><tr><td>Mold Star 15 SLOW</td><td>Smooth-On</td><td>NA</td><td></td></tr><tr><td>Oil-Resistant Buna-N O-Ring</td><td>McMaster-Carr</td><td>SN: 9262K141</td><td></td></tr><tr><td>Oxalic Acid, 98%, Anhydrous Powder (C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)&amp;nbsp;</td><td>Thermo Scientific&amp;nbsp;</td><td>CAS: 144-62-7</td><td></td></tr><tr><td>Rubber Band Expansion Tool</td><td>iplusmile</td><td>NA</td><td></td></tr><tr><td>Separated Vegetable Cellulose Capsules (Size #3)</td><td>Capsule Connection</td><td>NA</td><td></td></tr><tr><td>Smiley Face YoYo Latex balloon</td><td>YoYo Balloons, Etc.</td><td>NA</td><td></td></tr><tr><td>Sodium Bicarbonate Powder (CHNaO&lt;sub&gt;3&lt;/sub&gt;)&amp;nbsp;</td><td>Sigma</td><td>CAS: 144-55-8</td><td></td></tr><tr><td>Spectra Fiber Braided Fishing Line (50 lbs.)</td><td>Power Pro</td><td>NA</td><td></td></tr></tbody></table>

balloon tag manufacturing technique for sensor fish and live fish recovery

Fish may experience injuries and mortality when they pass through hydraulic conveyances at hydropower dams, even if these conveyances are designed to be fish-friendly, such as downstream bypass systems, modified spillways&#160;and turbines. The main methods used to study fish passage conditions in hydraulic structures involve direct, in situ testing using Sensor Fish technology and live fish. Sensor Fish data helps identify physical stressors and their locations in the fish passage environment, while live fish are assessed for injuries and mortality. Balloon tags, which are self-inflating balloons attached externally to Sensor Fish and live fish, aid in their recovery after passing through hydraulic structures.
This article focuses on the development of balloon tags with varying numbers of dissolvable, vegetable-based capsules containing a mixture of oxalic acid, sodium bicarbonate powders, and water at two different temperatures. Our research determined that balloon tags with three capsules, injected with 5 mL of water at 18.3 &#176;C, consistently achieved the desired balloon volume. These tags had a mean inflation volume of 114 cm3 with a standard deviation of 1.2 cm3. Among the balloon tags injected with water at 18.3 &#176;C, it was observed that the two-capsule balloon tags took the longest time to reach full inflation. In addition, the four-capsule balloon tags demonstrated a faster inflation start time, while the three-capsule balloon tags demonstrated a faster deflation start time. Overall, this approach proves to be effective for validating the performance of new technologies, improving turbine design, and making operational decisions to enhance fish passage conditions. It serves as a valuable tool for research and field evaluations, aiding in the refinement of both the design and operation of hydraulic structures.

A study was conducted to determine the optimal methods for manufacturing balloon tags, focusing on the volume and temperature of water injected into the balloon. The study examined various input parameters, including the inflation start time, full inflation time, deflation start time, and the volume of the balloon at full inflation. The study was conducted at a desk with an ambient temperature of 21 &#176;C.
A total of 360 balloon tags were prepared for the study. The tags were divided into 36...

Watch this Scientific Journal Video about Developing Cost-Effective and Customizable Balloon Tags for Fish Passage Studies at JoVE.com

Author Spotlight: Developing Cost-Effective and Customizable Balloon Tags for Fish Passage Studies 

A protocol is presented for designing and manufacturing balloon tags to recover Sensor Fish and live fish, allowing assessment of their physical condition and biological performance in hydraulic structures. The method optimizes balloon tag performance by considering factors such as balloon volume, inflation/deflation times, component selection, and the characteristics of the injected water.

Balloon Tag Manufacturing Technique for Sensor Fish and Live Fish Recovery

Fish may experience injuries and mortality when they pass through hydraulic conveyances at hydropower dams, even if these conveyances are designed to be ...

balloon-tag-manufacturing-technique-for-sensor-fish-live-fish

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Engineering

1.5K Views.  Pacific Northwest National Laboratory. A protocol is presented for designing and manufacturing balloon tags to recover Sensor Fish and live fish, allowing assessment of their physical condition and biological performance in hydraulic structures. The method optimizes balloon tag performance by considering factors such as balloon volume, inflation/deflation times, component selection, and the characteristics of the injected water.

Video: Author Spotlight: Developing Cost-Effective and Customizable Balloon Tags for Fish Passage Studies 

Synthesis and Characterization of High c-axis ZnO Thin Film by Plasma Enhanced Chemical Vapor Deposition System and its UV Photodetector Application

In this study, zinc oxide (ZnO) thin films with high c-axis (0002) preferential orientation have been successfully and effectively synthesized onto silicon (Si) substrates via different synthesized temperatures by using plasma enhanced chemical vapor deposition (PECVD) system. The effects of different synthesized temperatures on the crystal structure, surface morphologies and optical properties have been investigated. The X-ray diffraction (XRD) patterns indicated that the intensity of (0002) diffraction peak became stronger with increasing synthesized temperature until 400 oC. The diffraction intensity of (0002) peak gradually became weaker accompanying with appearance of (10-10) diffraction peak as the synthesized temperature up to excess of 400 oC. The RT photoluminescence (PL) spectra exhibited a strong near-band-edge (NBE) emission observed at around 375 nm and a negligible deep-level (DL) emission located at around 575 nm under high c-axis ZnO thin films. Field emission scanning electron microscopy (FE-SEM) images revealed the homogeneous surface and with small grain size distribution. The ZnO thin films have also been synthesized onto glass substrates under the same parameters for measuring the transmittance.
For the purpose of ultraviolet (UV) photodetector application, the interdigitated platinum (Pt) thin film (thickness ~100 nm) fabricated via conventional optical lithography process and radio frequency (RF) magnetron sputtering. In order to reach Ohmic contact, the device was annealed in argon circumstances at 450 oC by rapid thermal annealing (RTA) system for 10 min. After the systematic measurements, the current-voltage (I-V) curve of photo and dark current and time-dependent photocurrent response results exhibited a good responsivity and reliability, indicating that the high c-axis ZnO thin film is a suitable sensing layer for UV photodetector application.

We offered a method to directly synthesize high c-axis (0002) ZnO thin film by plasma enhanced chemical vapor deposition. The as-synthesized ZnO thin film combined with Pt interdigitated electrode was used as sensing layer for ultraviolet photodetector, showing a high performance through a combination of its good responsivity and reliability.

In this study, zinc oxide (ZnO) thin films with high c-axis (0002) preferential orientation have been successfully and effectively synthesized onto ...

How to Build a Vacuum Spring-transport Package for Spinning Rotor Gauges

The spinning rotor gauge (SRG) is a high-vacuum gauge often used as a secondary or transfer standard for vacuum pressures in the range of 1.0 x 10-4 Pa to 1.0 Pa. In this application, the SRGs are frequently transported to laboratories for calibration. Events can occur during transportation that change the rotor surface conditions, thus changing the calibration factor. To assure calibration stability, a spring-transport mechanism is often used to immobilize the rotor and keep it under vacuum during transport. It is also important to transport the spring-transport mechanism using packaging designed to minimize the risk of damage during shipping. In this manuscript, a detailed description is given on how to build a robust spring-transport mechanism and shipping container. Together these form a spring-transport package. The spring-transport package design was tested using drop-tests and the performance was found to be excellent. The present spring-transport mechanism design keeps the rotor immobilized when experiencing shocks of several hundred g (g = 9.8 m/sec2 and is the acceleration due to gravity), while the shipping container assures that the mechanism will not experience shocks greater than about 100 g during common shipping mishaps (as defined by industry standards).

Here we describe how to build a robust spring-transport mechanism for a spinning rotor gauge. This device securely immobilizes the rotor and keeps it under vacuum during transportation. We also describe packaging that minimizes the risk of damage during transport. Tests show our design works for typical shocks during transport.

The spinning rotor gauge (SRG) is a high-vacuum gauge often used as a secondary or transfer standard for vacuum pressures in the range of 1.0 x 10-4 Pa to ...

Digital Printing of Titanium Dioxide for Dye Sensitized Solar Cells

Silicon solar cell manufacturing is an expensive and high energy consuming process. In contrast, dye sensitized solar cell production is less environmentally damaging with lower processing temperatures presenting a viable and low cost alternative to conventional production. This paper further enhances these environmental credentials by evaluating the digital printing and therefore additive production route for these cells. This is achieved here by investigating the formation and performance of a metal oxide photoelectrode using nanoparticle sized titanium dioxide. An ink-jettable material was formulated, characterized and printed with a piezoelectric inkjet head to produce a 2.6 &#181;m thick layer. The resultant printed layer was fabricated into a functioning cell with an active area of 0.25 cm2 and a power conversion efficiency of 3.5%. The binder-free formulation resulted in a reduced processing temperature of 250 &#176;C, compatible with flexible polyamide substrates which are stable up to temperatures of 350 &#730;C. The authors are continuing to develop this process route by investigating inkjet printing of other layers within dye sensitized solar cells.

This paper investigates the suitability of inkjet printing for the manufacturing of dye-sensitized solar cells. A binder-free TiO2 nanoparticle ink was formulated and printed onto a FTO glass substrate. The printed layer was fabricated into a cell with an active area of 0.25 cm2 and an efficiency of 3.5%.

Silicon solar cell manufacturing is an expensive and high energy consuming process. In contrast, dye sensitized solar cell production is less ...

Basic Methods for the Study of Reproductive Ecology of Fish in Aquaria

Captive-rearing observations are valuable for revealing aspects of fish behavior and ecology when continuous field investigations are impossible. Here, a series of basic techniques are described to enable observations of the reproductive behavior of a wild-caught gobiid fish, as a model, kept in an aquarium. The method focuses on three steps: collection, transport, and observations of reproductive ecology of a substrate spawner. Essential aspects of live fish collection and transport are (1) preventing injury to the fish, and (2) careful acclimation to the aquarium. Preventing harm through injuries such as scratches or a sudden change of water pressure is imperative when collecting live fish, as any physical damage is likely to negatively affect the survival and later behavior of the fish. Careful acclimation to aquaria decreases the incidence death and mitigates the shock of transport. Observations during captive rearing include (1) the identification of individual fish and (2) monitoring spawned eggs without negative effects to the fish or eggs, thereby enabling detailed investigation of the study species' reproductive ecology. The subcutaneous injection of a visible implant elastomer (VIE) tag is a precise method for the subsequent identification of individual fish, and it can be used with a wide size range of fish, with minimal influence on their survival and behavior. If the study species is a substrate spawner that deposits adhesive eggs, an artificial nest site constructed from polyvinyl chloride (PVC) pipe with the addition of a removable waterproof sheet will facilitate counting and monitoring the eggs, lessening the investigator's influence on the nest-holding and egg-guarding behavior of the fish. Although this basic method entails techniques that are seldom mentioned in detail in research articles, they are fundamental for undertaking experiments that require the captive rearing of a wild fish.

A series of basic methods to enable the study of the reproductive ecology of fish kept in aquaria are described. These are useful protocols for collecting fish using SCUBA, transporting live fish, and observing the reproductive behavior of wild-caught fish kept in aquaria.

Captive-rearing observations are valuable for revealing aspects of fish behavior and ecology when continuous field investigations are impossible. Here, a ...

Behavior

Implantation of a New Micro Acoustic Tag in Juvenile Pacific Lamprey and American Eel

Juvenile Pacific Lamprey and American eels were used for laboratory evaluations to determine potential effects from tag implantation. Telemetry technology has been identified as a way to obtain more detailed information on movement and behavior across a broader spatial scale than is possible with other known technology. The purpose of this method is to provide a detailed step by step instruction on tag implantation for both lampreys and eel. For laboratory studies using actively migrating juvenile Pacific Lamprey (120-160 mm), we determined that the presence of the tag did not alter the swimming ability between tagged and untagged Individuals or have any significant tag loss (&lt;3%). Similar results were determined during laboratory testing of Yellow phase American Eels (113-175 mm). No mortality occurred during a 38-day holding period and there was minimal tag loss (3.8%). The presence of the tag did not have any significant effect on the swimming ability or survival of tagged eels compared to untagged controls and there was minimal tag loss.

This article illustrates the procedure for implanting a micro acoustic tag in juvenile Pacific Lamprey and American Eel. Our application is based on laboratory trials, which indicate that acoustic tags can be successfully implanted with no apparent effects on swimming ability or survival and minimal tag loss.

Juvenile Pacific Lamprey and American eels were used for laboratory evaluations to determine potential effects from tag implantation. Telemetry technology ...

Environment

An Available Technique for Preparation of New Cast MnCuNiFeZnAl Alloy with Superior Damping Capacity and High Service Temperature

Manganese (Mn)-copper (Cu)-based alloys have been found to have&#160;damping capacity and can be used to reduce harmful vibrations and noise effectively. M2052 (Mn-20Cu-5Ni-2Fe, at%) is an important branch of Mn-Cu-based alloys, which possesses both excellent damping capacity and processability. In recent decades, lots of studies have been carried out on the performance optimization of M2052, improving the damping capacity, mechanical properties, corrosion resistance, and service temperature, etc. The major methods of performance optimization are alloying, heat treatment, pretreatment, and different ways of molding etc., among which alloying, as well as adopting a reasonable heat treatment, is the simplest and most effective method to obtain perfect and comprehensive performance. To obtain the M2052 alloy with excellent performance for casting molding, we propose to add Zn and Al to the MnCuNiFe alloy matrix and use a variety of heat treatment methods for a comparison in the microstructure, damping capacity, and service temperature. Thus, a new type of cast-aged Mn-22.68Cu-1.89Ni-1.99Fe-1.70Zn-6.16Al (at.%) alloy with&#160;superior damping capacity and high service temperature is obtained by an optimized heat treatment method. Compared with the forging technique, cast molding is simpler and more efficient, and the damping capacity of this as-cast alloy is excellent. Therefore, there is a suitable reason to think that it is a good choice for engineering applications.

Here we present a protocol to obtain a novel Mn-Cu-based alloy with excellent comprehensive performances by a high-quality smelting technology and reasonable heat treatment methods.

Manganese (Mn)-copper (Cu)-based alloys have been found to have&#160;damping capacity and can be used to reduce harmful vibrations and noise effectively. ...

Magnet Assisted Composite Manufacturing: A Flexible New Technique for Achieving High Consolidation Pressure in Vacuum Bag/Lay-Up Processes

This work demonstrates a protocol to improve the quality of composite laminates fabricated by wet lay-up vacuum bag processes using the recently developed magnet assisted composite manufacturing (MACM) technique. In this technique, permanent magnets are utilized to apply a sufficiently high consolidation pressure during the curing stage. To enhance the intensity of the magnetic field, and thus, to increase the magnetic compaction pressure, the magnets are placed on a magnetic top plate. First, the entire procedure of preparing the composite lay-up on a magnetic bottom steel plate using the conventional wet lay-up vacuum bag process is described. Second, placement of a set of Neodymium-Iron-Boron permanent magnets, arranged in alternating polarity, on the vacuum bag is illustrated. Next, the experimental procedures to measure the magnetic compaction pressure and volume fractions of the composite constituents are presented. Finally, methods used to characterize microstructure and mechanical properties of composite laminates are discussed in detail. The results prove the effectiveness of the MACM method in improving the quality of wet lay-up vacuum bag laminates. This method does not require large capital investment for tooling or equipment and can also be used to consolidate geometrically complex composite parts by placing the magnets on a matching top mold positioned on the vacuum bag.

A new technique for applying consolidation pressure on the vacuum bag lay-up to fabricate composite laminates is described. The goal of this protocol is to develop a simple, cost-effective technique to improve the quality of laminates fabricated by the wet lay-up vacuum bag method.

This work demonstrates a protocol to improve the quality of composite laminates fabricated by wet lay-up vacuum bag processes using the recently developed ...

Long-term Behavioral Tracking of Freely Swimming Weakly Electric Fish

Long-term behavioral tracking can capture and quantify natural animal behaviors, including those occurring infrequently. Behaviors such as exploration and social interactions can be best studied by observing unrestrained, freely behaving animals. Weakly electric fish (WEF) display readily observable exploratory and social behaviors by emitting electric organ discharge (EOD). Here, we describe three effective techniques to synchronously measure the EOD, body position, and posture of a free-swimming WEF for an extended period of time. First, we describe the construction of an experimental tank inside of an isolation chamber designed to block external sources of sensory stimuli such as light, sound, and vibration. The aquarium was partitioned to accommodate four test specimens, and automated gates remotely control the animals&#39; access to the central arena. Second, we describe a precise and reliable real-time EOD timing measurement method from freely swimming WEF. Signal distortions caused by the animal&#39;s body movements are corrected by spatial averaging and temporal processing stages. Third, we describe an underwater near-infrared imaging setup to observe unperturbed nocturnal animal behaviors. Infrared light pulses were used to synchronize the timing between the video and the physiological signal over a long recording duration. Our automated tracking software measures the animal&#39;s body position and posture reliably in an aquatic scene. In combination, these techniques enable long term observation of spontaneous behavior of freely swimming weakly electric fish in a reliable and precise manner. We believe our method can be similarly applied to the study of other aquatic animals by relating their physiological signals with exploratory or social behaviors.

We describe a set of techniques for studying spontaneous behavior of freely swimming weakly electric fish over an extended period of time, by synchronously measuring the animal&#39;s electric organ discharge timing, body position and posture both accurately and reliably in a specially designed aquarium tank inside a sensory isolation chamber.

Long-term behavioral tracking can capture and quantify natural animal behaviors, including those occurring infrequently. Behaviors such as exploration and ...

Neuroscience

Handling and Tagging Techniques for Implanting Juvenile American Shad with a New Acoustic Microtransmitter

The use of telemetry techniques to better understand the behavior and survival of juvenile American shad (Alosa sapidissima), as they migrate through hydropower systems, has been challenging because shad are widely known to be particularly sensitive to handling. The goal of this study was to develop a tagging protocol using a new, acoustic micro transmitter that minimizes the detrimental effects of the tagging process and maximizes post-tagging survival of juvenile American shad. Limiting out-of-water handling and the use of brackish saltwater (7.5 parts per thousand) before and after tagging improved survival for shad tagged using a simple pectoral implantation method. This protocol provides a detailed, step-by-step procedure for tagging juvenile shad with acoustic transmitters. Fish tagged using this procedure and held in the laboratory for 60 days had an 81.5% survival rate, compared to 70% for their untagged counterparts. The successful tagging and handling practices developed in this study could be applied to field telemetry studies of juvenile shad and other sensitive species.

This article provides a detailed procedure for optimal handling practices and implantation of an acoustic micro transmitter into juvenile American shad. The results of our laboratory study suggest that these tagging techniques could be implemented in field studies of juvenile American shad with a high probability of survival.

The use of telemetry techniques to better understand the behavior and survival of juvenile American shad (Alosa sapidissima), as they migrate through ...

Wireless Electrophysiological Recording of Neurons by Movable Tetrodes in Freely Swimming Fish

The neural mechanisms governing fish behavior remain mostly unknown, although fish constitute the majority of all vertebrates. The ability to record brain activity from freely moving fish would advance research on the neural basis of fish behavior considerably. Moreover, precise control of the recording location in the brain is critical to studying coordinated neural activity across regions in fish brain. Here, we present a technique that records wirelessly from the brain of freely swimming fish while controlling for the depth of the recording location. The system is based on a neural logger associated with a novel water-compatible implant that can adjust the recording location by microdrive-controlled tetrodes. The capabilities of the system are illustrated through recordings from the telencephalon of goldfish.

A novel wireless technique for recording extracellular neural signals from the brain of freely swimming goldfish is presented. The recording device is composed of two tetrodes, a microdrive, a neural data logger, and a waterproof case. All parts are custom-made except for the data logger and its connector.

The neural mechanisms governing fish behavior remain mostly unknown, although fish constitute the majority of all vertebrates. The ability to record brain ...