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At least 577 records · Page 32
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Designing the PLANET Chamber for Lunar Environment Ground Testing

The Planetary, Lunar, and Asteroid Natural Environments Testbed (PLANET) is a new 2m x 3m high-vacuum chamber facility currently being designed and built at NASA’s Marshall Space Flight Center. When completed, it will be one of the highest-fidelity space/surface environment simulation chambers in existence. Instrumented with equipment to produce charged particle radiation, full spectrum ultraviolet, low-density plasma, and thermal extremes, PLANET can be configured to recreate the most challenging space environments. Additionally, a large regolith bed and distribution system will expose hardware to lunar regolith simulants and dust. This paper will describe the process of designing and optimizing PLANET and discuss some common considerations for performing ground-based environmental testing for lunar exploration.

Erin G Hayward↗
NASA NTRS1972

Design and development of pressure and repressurization purge system for reusable space shuttle multilayer insulation system

The experimental determination of purge bag materials properties, development of purge bag manufacturing techniques, experimental evaluation of a subscale purge bag under simulated operating conditions and the experimental evaluation of the purge pin concept for MLI purging are discussed. The basic purge bag material, epoxy fiberglass bounded by skins of FEP Teflon, showed no significant permeability to helium flow under normal operating conditions. Purge bag small scale manufacturing tests were conducted to develop tooling and fabrication techniques for use in full scale bag manufacture. A purge bag material layup technique was developed whereby the two plys of epoxy fiberglass enclosed between skins of FEP Teflon are vacuum bag cured in an oven in a single operation. The material is cured on a tool with the shape of a purge bag half. Plastic tooling was selected for use in bag fabrication. A model purge bag 0.6 m in diameter was fabricated and subjected to a series of structural and environmental tests simulating various flight type environments. Pressure cycling tests at high (450 K) and low (200 K) temperature as well as acoustic loading tests were performed. The purge bag concept proved to be structurally sound and was used for the full scale bag detailed design model.

Source record↗
NASA NTRS1973

An experimental evaluation of metallic diaphragms for positive fuel expulsion in the atmosphere explorer hydrazine propulsion subsystem

Four Arde conospheroid metallic diaphragms were tested to evaluate their capability for use in the orbit adjust propulsion subsystem (OAPS) of the Explorer spacecraft. The diaphragms will be used for positive propellant expulsion and spacecraft center of mass control. A leak-free cycle life capability of nine reversals was demonstrated. The diaphragms rolled smoothly from ring to ring in a predictable manner on the first reversal. Varying amounts of diaphragm cocking and ring skipping were observed on subsequent reversals. The diaphragm pressure differential did not exceed 7 N/sq cm during any reversal. Cycle life capability, reversal mode, and pressure differential were not affected by sudden reversals, environmental tests, or 18,000 partial reversals. An expulsion efficiency of approximately 97 percent was demonstrated. The results of these tests show that metallic diaphragms can be used as an effective means of positive fuel expulsion; however, to achieve spacecraft center of mass control, the diaphragm must not be reversed prior to flight.

Woodruff, W. L.↗
NASA NTRSDate not supplied

Investigating Material Behavior in Atmospheric Entry Conditions: Arc-Jet Testing Insights from Meteorite Ablation to High-Temperature Coatings.

Arc-jet testing is an indispensable tool in elucidating the complex interactions materials undergo when subjected to the extreme thermal and mechanical stresses of atmospheric entry. By replicating these harsh conditions, arc-jets enable researchers to explore critical phenomena such as ablation, melting, and spallation, generating invaluable data that informs the development of sophisticated, physics-based models. These models are pivotal not only in predicting material performance for spacecraft re-entry systems but also in assessing the threat posed by celestial bodies as they encounter Earth’s atmosphere. One of the leading facilities for such investigations is the Hypersonic Materials Environmental Test System (HyMETS) at NASA’s Langley Research Center. A pioneering test campaign conducted at HyMETS focused on unraveling the ablation mechanisms of an ordinary chondrite meteorite (Tamdakht H5) and a terrestrial analog (basalt). These studies unveiled distinct material behaviors: Tamdakht demonstrated a remarkably stable melt flow, with mass loss primarily driven by the volatilization of elements such as iron and sodium, whereas basalt exhibited more aggressive surface degradation due to the rapid decomposition of hydrated minerals, culminating in significant spallation and surface material ejection. Beyond meteorite analysis, HyMETS has also been integral in the exploration of advanced Thermal Protection Systems (TPS) such as Phenolic Impregnated Carbon Ablator (PICA), a material with extensive flight heritage in missions like Stardust, Mars Science Laboratory, Mars 2020, and Osiris-REx. PICA, when coated with NuSil CV-1144-0—a polysiloxane resin designed to prevent particle shedding—undergoes a remarkable transformation upon heating. The resin pyrolyzes to form a thin, oxidation-resistant silicon oxycarbide layer that profoundly influences the material’s thermal response through a sophisticated four-stage process. Initially, the silicon oxycarbide acts as a formidable barrier, impeding reactive interactions with the PICA char and effectively suppressing surface temperature rise and material recession. However, as the heating persists, the protective layer decomposes via carbothermal reduction, exposing the underlying char, which in turn leads to a dramatic spike in surface temperature and accelerated material erosion. In the final stage, equilibrium is reached, with recession rates aligning with those of the virgin material. This intricate understanding of PICA-NuSil behavior under extreme conditions offers valuable insights, enhancing material response models and advancing the development of next-generation TPS for space exploration.

Chemistry↗
NASA NTRS1987

Environmental degradation of 316 stainless steel in high temperature low cycle fatigue

Procedures based on modification of the conventional Strainrange Partitioning method are proposed to characterize the time-dependent degradation of engineering alloys in high-temperature, low-cycle fatigue. Creep-fatigue experiments were conducted in air using different waveforms of loading on 316 stainless steel at 816 C (1500 F) to determine the effect of exposure time on cyclic life. Reductions in the partitioned cyclic lives were observed with an increase in the time of exposure (or with the corresponding decrease in the steady-state creep rate) for all the waveforms involving creep strain. Excellent correlations of the experimental data were obtained by modifying the Conventional Strainrange Partitioning life relationships involving creep strain using a power-law term of either: (1) time of exposure, or (2) steady-state creep rate of the creep-fatigue test. Environmental degradation due to oxidation, material degradation due to the precipitation of carbides along the grain boundaries and detrimental deformation modes associated with the prolonged periods of creep were observed to be the main mechanisms responsible for life reductions at long exposure times.

Kalluri, Sreeramesh↗
NASA NTRS1973

An experimental evaluation of metallic diaphragms for positive fuel expulsion in the Atmosphere Explorer, hydrazine propulsion subsystem

Four Arde conospheroid metallic diaphragms were tested at NASA to evaluate their capability for use in the orbit adjust propulsion subsystem (OAPS) of the Atmosphere Explorer spacecraft (AE's C, D, and E). The diaphragms will be used for positive propellant expulsion and spacecraft center of mass (c.m.) control. A leak-free cycle life capability of nine reversals was demonstrated. The diaphragms rolled smoothly from ring to ring in a predictable manner on the first reversal. Varying amounts of diaphragm cocking and ring skipping were observed on subsequent reversals. The diaphragm pressure differential did not exceed 10 psid during any reversal. Cycle life capability, reversal mode, and pressure differential were not affected by sudden reversals, environmental tests, or 18,000 partial reversals. An expulsion efficiency of approximately 97 percent was demonstrated. The results of these tests show that metallic diaphragms can be used as an effective means of positive fuel expulsion; however, to achieve spacecraft c.m. control, the diaphragm must not be reversed prior to flight.

Woodruff, W. L.↗
NASA NTRS2003

Geoscience Laser Altimeter System (GLAS) on the ICESat Mission: Initial Science Measurement Performance

The Geoscience Laser Altimeter System is the space lidar on the NASA ICESat mission. Its design combines an altimeter with 5 cm precision with a laser pointing angle determination system and a dual wavelength cloud and aerosol lidar. GLAS measures the range to the Earth s surface with 1064 nm laser pulses. Each laser pulse produces a precision pointing measurement from the stellar reference system (SRS) and an echo pulse waveform, which permits range determination and waveform spreading analysis. The single shot ranging accuracy is < 10 cm for ice surfaces with slopes < 2 degrees. GLAS also measures atmospheric backscatter profiles at both 1064 and 532 nm. The 1064 nm measurements use an analog Si APD detector and measure the height and profile the backscatter signal from thicker clouds. The measurements at 532 nm use photon counting detectors, and will measure the vertical height distributions of optically thin clouds and aerosol layers Before launch, the measurement performance of GLAS was evaluated using a lidar test instrument called the Bench Check Equipment (BCE). The BCE was developed in parallel with GLAS and served as an inverse altimeter, inverse lidar and a stellar source simulator. It was used to simulate the range of expected optical inputs to the GLAS receiver by illuminating its telescope with simulated background light as well as laser echoes with known powers, energy levels, widths and delay times. The BCE also allowed monitoring of the transmitted laser energy, the angle measurements of the SRS, the co-alignment of the transmitted laser beam to the receiver line of sight, and performance of the flight science algorithms. Performance was evaluated during the GLAS development, before and after environmental tests, and after delivery to the spacecraft. The ICESat observatory was launched into a 94 degree inclination, 590 km altitude circular polar orbit on January 12,2003. Beginning in early February, GLAS was powered on tested in stages. Its 1064 nm optical receiver was evaluated in a several tests using both solar background light and an internal test source. Laser 1 was activated on February 20,2003. GLAS operated with Laser 1 for 38 continuous days on orbit using its 1064 nm receiver channel, producing over 130 million individual laser measurements of the Earth s surface and atmosphere. These nadir-pointed measurements fell along the ICESat s ground track, and spanned more than 4 cycles of the initial 8-day ICESat repeat orbit. The initial GLAS measurement set shows strong echo pulses from ranging to the surface topography, oceans, ice sheets and cloud tops, as well as profiles of clouds and aerosols. The GLAS measurements have unprecedented vertical and angular resolution, and show nearly continuous height profiles of ice, land and ocean surfaces or cloud tops, as well profiles of backscatter from thin clouds and aerosol layers. Examples of these GLAS measurements and an initial assessment of its science measurement performance will be presented.

Abshire, James B.↗
NASA NTRSDate not supplied

Performance of the Dragonfly Mass Spectrometer (DraMS) Programmable UV Laser Source Engineering Test Unit (ETU)

NASA’s Dragonfly mission will sample surface materials from multiple sites on Saturn’s largest moon, Titan, in exploration of its potential for prebiotic chemistry. We report on the performance of our short-pulsed UV laser transmitter, developed for the Dragonfly’s on-board Mass Spectrometer (DraMS). Our engineering test unit (ETU) has completed flight qualification and demonstrated its operational science requirements, such that the final flight unit build can begin. The Titan Hydrocarbon Analysis Nanosecond Optical Source (THANOS) ETU laser produces 266 nm laser pulses at programmable energy levels in order to create high resolution laser desorption mass spectrometry (LDMS) measurements. The laser operates in short bursts of 1-50 pulses, each at < 2 ns pulse width, at a 100 Hz repetition rate. Creating a sealed Titanium unit, capable of operation on the extreme environment of Titan’s surface was a major engineering challenge. The laser successfully demonstrated its ability to meet all operational requirements in terms of pulse energy, beam pointing on target and repeatability even after extensive environmental testing.

Matthew W Mullin↗
NASA NTRSDate not supplied

Performance of the Dragonfly Mass Spectrometer (DraMS) Programmable UV Laser Source Engineering Test Unit (ETU)

NASA’s Dragonfly mission will sample surface materials from multiple sites on Saturn’s largest moon, Titan, in exploration of its potential for prebiotic chemistry. We report on the performance of our short-pulsed UV laser transmitter, developed for the Dragonfly’s on-board Mass Spectrometer (DraMS). Our engineering test unit (ETU) has completed flight qualification and demonstrated its operational science requirements, such that the final flight unit build can begin. The Titan Hydrocarbon Analysis Nanosecond Optical Source (THANOS) ETU laser produces 266 nm laser pulses at programmable energy levels in order to create high resolution laser desorption mass spectrometry (LDMS) measurements. The laser operates in short bursts of 1-50 pulses, each at < 2 ns pulse width, at a 100 Hz repetition rate. Creating a sealed Titanium unit, capable of operation on the extreme environment of Titan’s surface was a major engineering challenge. The laser successfully demonstrated its ability to meet all operational requirements in terms of pulse energy, beam pointing on target and repeatability even after extensive environmental testing.

Matthew Mullin↗
NASA NTRS1981

Diagnostic system design for the Ion Auxiliary Propulsion System /IAPS/ - Flight test of two 8 cm mercury ion thrusters

The experimental design of a Diagnostic Subsystem (DSS) as part of an Ion Auxiliary Propulsion System (IAPS) to be flown on P80-1 spacecraft in May 1983, is discussed. The DSS is composed of several detectors measuring thruster efflux, material deposition and spacecraft potential relative to the local space plasma in the vicinity of two 8 cm mercury ion thrusters. The detectors consist of two QCM units measuring frequency in the range of two to 65 KHz. Nine solar cell arrays have the capability of measuring current and voltage from 0-600 mA and 0-0.9 V. Seven ion collectors can measure ion currents with bias voltages of 0, 25, 55 and 96 V. The potential probe can measure current at 16 different commandible levels varying from one to 5 K microamperes within a voltage range of -25 to 175 V. The analysis of the ground-based data indicates that the hardware is qualified for flight, with the detectors and electronic units having passed all functional and environmental tests. Block diagrams are given and the functional parameters of the different design configurations are described.

Hurst, E. B.↗
NASA NTRS2010

Design and Testing of an Active Heat Rejection Radiator with Digital Turn-Down Capability

NASA's proposed lunar lander, Altair, will be exposed to vastly different external environment temperatures. The challenges to the active thermal control system (ATCS) are compounded by unfavorable transients in the internal waste heat dissipation profile: the lowest heat load occurs in the coldest environment while peak loads coincide with the warmest environment. The current baseline for this fluid is a 50/50 inhibited propylene glycol/water mixture with a freeze temperature around -35 C. While the overall size of the radiator's heat rejection area is dictated by the worst case hot scenario, a turn-down feature is necessary to tolerate the worst case cold scenario. A radiator with digital turn-down capability is being designed as a robust means to maintain cabin environment and equipment temperatures while minimizing mass and power consumption. It utilizes active valving to isolate and render ineffective any number of parallel flow tubes which span across the ATCS radiator. Several options were assessed in a trade-study to accommodate flow tube isolation and how to deal with the stagnant fluid that would otherwise remain in the tube. Bread-board environmental tests were conducted for options to drain the fluid from a turned-down leg as well an option to allow a leg to freeze/thaw. Each drain option involved a positive displacement gear pump with different methods of providing a pressure head to feed it. Test results showed that a start-up heater used to generate vapor at the tube inlet held the most promise for tube evacuation. Based on these test results and conclusions drawn from the trade-study, a full-scale radiator design is being worked for the Altair mission profile.

Sunada, Eric↗
NASA NTRS2019

MEDLI2 Flight Heat Flux Sensor Environment and Planetary Protection Testing

Mars 2020 will fly the Mars Entry, Descent, and Landing Instrumentation II (MEDLI2) sensor suite consisting of a total of seventeen instrumented thermocouple sensor plugs, eight pressure transducers, two total heat flux sensors, and one radiometer embedded in the thermal protection system (TPS). Of the MEDLI2 instrumentation, eleven instrumented thermocouple plugs and seven pressure transducers will be installed on the heatshield of the Mars 2020 vehicle while the rest will be installed on the backshell. The goal of the MEDLI2 instrumentation is to directly inform the large performance uncertainties that contribute to the design and validation of a Mars entry system. A better understanding of the entry environment and TPS performance could lead to reduced design margins enabling greater payload mass-fraction and smaller landing ellipses. The MEDLI2 total heat flux sensors and radiometer are new instruments that were not flown on the Mars Science Laboratory mission. These sensors directly measure the surface heat flux and radiation at specific backshell locations. The total heat flux sensors use a Schmidt-Boelter sensing element. The radiometer version uses a sapphire window placed over the Schmidt-Boelter sensing element to separate the radiative component of the total heat flux. MEDLI2 recently planned and executed protoflight environmental testing as well planetary protection measures on the flight and flight-spare total heat flux sensors and radiometers. This testing is required to provide confidence in the performance of the flight-lot sensors when exposed to flight-like environments, and to reduce the risk of biological contamination on the planet of Mars with microbes from Earth.

MEDLI2 FLIGHT HEAT FLUX SENSOR ENVIRONMENT AND PLA↗
DOE OSTI2024

Lab Evaluation of Downward Capacity of Radiant Ceiling Panel Systems

This project investigated the cooling delivery effectiveness of radiant ceiling panels as a function of attic insulation level using multiple laboratory testing and analytical methodologies. Delivery effectiveness is the heating or cooling energy delivered to a conditioned space divided by the total heating or cooling energy added or removed by the space conditioning system. The lower the losses of the heating or cooling delivery method, the higher the delivery effectiveness. For ducted systems, delivery effectiveness is reduced by both air leakage and thermal losses (especially if the ducts are installed in attics), while the delivery effectiveness of a radiant system supplied by hot and cold water is only reduced by thermal losses, which can be mitigated by sufficient insulation above, or at the "back" of the panel. Being installed at or below the ceiling plane, sufficient back insulation should be provided by default in the form of the attic insulation above the radiant ceiling panels. Site-built radiant ceiling panels were evaluated at Frontier Energy’s Building Science Research Laboratory (BSRL) in a uniquely designed environmental test chamber with independently controllable indoor and attic spaces and a height-adjustable ceiling.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
NASA NTRS2005

Materials on the International Space Station - Forward Technology Solar Cell Experiment

This paper describes a space solar cell experiment currently being built by the Naval Research Laboratory (NRL) in collaboration with NASA Glenn Research Center (GRC), and the US Naval Academy (USNA). The experiment has been named the Forward Technology Solar Cell Experiment (FTSCE), and the purpose is to rapidly put current and future generation space solar cells on orbit and provide validation data for these technologies. The FTSCE is being fielded in response to recent on-orbit and ground test anomalies associated with space solar arrays that have raised concern over the survivability of new solar technologies in the space environment and the validity of present ground test protocols. The FTSCE is being built as part of the Fifth Materials on the International Space Station (MISSE) Experiment (MISSE-5), which is a NASA program to characterize the performance of new prospective spacecraft materials when subjected to the synergistic effects of the space environment. Telemetry, command, control, and communication (TNC) for the FTSCE will be achieved through the Amateur Satellite Service using the PCSat2 system, which is an Amateur Radio system designed and built by the USNA. In addition to providing an off-the-shelf solution for FTSCE TNC, PCSat2 will provide a communications node for the Amateur Radio satellite system. The FTSCE and PCSat2 will be housed within the passive experiment container (PEC), which is an approximately 2ft x2ft x 4in metal container built by NASA Langley Research Center (NASA LaRC) as part of the MISSE-5 program. NASA LaRC has also supplied a thin film materials experiment that will fly on the exterior of the thermal blanket covering the PCSat2. The PEC is planned to be transported to the ISS on a Shuttle flight. The PEC will be mounted on the exterior of the ISS by an astronaut during an extravehicular activity (EVA). After nominally one year, the PEC will be retrieved and returned to Earth. At the time of writing this paper, the subsystems of the experiment are being integrated at NRL, and we are preparing to commence environmental testing.

Walters, R. J.↗
DOE OSTI2023

Experimental and theoretical investigations of rotating algae biofilm reactors (RABRs): Areal productivity, nutrient recovery, and energy efficiency

Microalgae biofilms have been demonstrated to recover nutrients from wastewater and serve as biomass feedstock for bioproducts. However, there is a need to develop a platform to quantitatively describe microalgae biofilm production, which can provide guidance and insights for improving biomass areal productivity and nutrient uptake efficiency. Here, this paper proposes a unified experimental and theoretical framework to investigate algae biofilm growth on a rotating algae biofilm reactor (RABR). Experimental laboratory setups are used to conduct controlled experiments on testing environmental and operational factors for RABRs. We propose a differential–integral equation‐based mathematical model for microalgae biofilm cultivation guided by laboratory experimental findings. The predictive mathematical model development is coordinated with laboratory experiments of biofilm areal productivity associated with ammonia and inorganic phosphorus uptake by RABRs. The unified experimental and theoretical tool is used to investigate the effects of RABR rotating velocity, duty cycle (DC), and light intensity on algae biofilm growth, areal productivity, nutrient uptake efficiency, and energy efficiency in wastewater treatment. Our framework indicates that maintaining a reasonable light intensity range improves biomass areal productivity and nutrient uptake efficiency. Our framework also indicates that faster RABR rotation benefits biomass areal productivity. However, maximizing the nutrient uptake efficiency requires a reasonably low RABR rotating speed. Energy efficiency is strongly correlated with RABR rotating speed and DC.

09 BIOMASS FUELS↗
DOE OSTI2023

Outgassing behavior and heat treatment optimization of JSC-1A lunar regolith simulant

As NASA strives towards a long duration presence on the Moon, it has become increasingly important to learn how to better utilize resources from the lunar surface for everything from habitats, vehicle infrastructure, and chemical extraction. To that end, a variety of lunar simulants have been sourced from terrestrially available volcanic minerals and glass as Apollo regolith is unavailable for experimentation needing large masses. However, while mineralogy and chemical composition can approach that of lunar material in these simulants, there are still distinct non-lunar phases such as hydrates, carbonates, sulfates, and clays that can cause simulants to behave distinctly non-lunar in a variety of processing conditions that maybe applied in-situ to lunar material. Notably, severe glassy bubbling has been documented in a variety of vacuum sintering experiments on JSC-1A lunar mare simulant heated via microwaves. The origins of this outgassing have not been well understood but are normally attributed to the decomposition of non-lunar contaminates intrinsic to virtually all terrestrially sourced simulants. As such, a series of controlled environmental tests were performed to ascertain the origins of the high temperature outgassing and to develop heat treatments that can drive JSC-1A closer to lunar composition and behavior. It was found that in JSC-1A at elevated temperatures distinct gas evolutions of water, carbon dioxide, and sulfur dioxide occur in both inert gas and vacuum. Additionally, the presence of hydrogen during heat treatments was shown to dramatically change gas evolutions, leading to distinctly more lunar-like composition and behavior from JSC-1A simulant.

58 GEOSCIENCES↗
DOE OSTI2025

Structural basis for saxitoxin congener binding and neutralization by anuran saxiphilins

Dinoflagellates and cyanobacteria produce saxitoxin (STX) and ~50 congeners that disrupt bioelectrical signals by blocking voltage-gated sodium channels (NaVs). Consuming seafood carrying these toxins causes paralytic shellfish poisoning (PSP). Although NaVs and anuran STX binding proteins (saxiphilins, Sxphs) use convergent STX binding modes, the structural basis for STX congener recognition is unknown. Here, we show that American bullfrog (Rana catesbeiana) RcSxph and High Himalaya frog (Nanorana parkeri) NpSxph sequester STX congeners using a ‘lock and key’ mode shared with STX. Importantly, functional studies demonstrate that Sxph ‘toxin sponges’ reverse NaV block by multiple STX congeners and detect these toxins in a radioligand binding assay (RBA) used for environmental testing. Together, our study establishes how Sxphs sequester select neurotoxins and uncover STX congener-specific interactions distinct from NaVs. These findings expand understanding of toxin sponge action and provide a foundation for strategies to monitor and mitigate the harmful effects of STX congeners.

Zakrzewska, Sandra↗
DOE OSTI2024

Impacts of humic substances, elevated temperature, and UVB radiation on bacterial communities of the marine sponge Chondrilla sp

Abstract Sponges are abundant components of coral reefs known for their filtration capabilities and intricate interactions with microbes. They play a crucial role in maintaining the ecological balance of coral reefs. Humic substances (HS) affect bacterial communities across terrestrial, freshwater, and marine ecosystems. However, the specific effects of HS on sponge-associated microbial symbionts have largely been neglected. Here, we used a randomized-controlled microcosm setup to investigate the independent and interactive effects of HS, elevated temperature, and UVB radiation on bacterial communities associated with the sponge Chondrilla sp. Our results indicated the presence of a core bacterial community consisting of relatively abundant members, apparently resilient to the tested environmental perturbations, alongside a variable bacterial community. Elevated temperature positively affected the relative abundances of ASVs related to Planctomycetales and members of the families Pseudohongiellaceae and Hyphomonadaceae. HS increased the relative abundances of several ASVs potentially involved in recalcitrant organic matter degradation (e.g., the BD2-11 terrestrial group, Saccharimonadales, and SAR202 clade). There was no significant independent effect of UVB and there were no significant interactive effects of HS, heat, and UVB on bacterial diversity and composition. The significant, independent impact of HS on the composition of sponge bacterial communities suggests that alterations to HS inputs may have cascading effects on adjacent marine ecosystems.

Stuij, Tamara M. (ORCID:0000000152170798)↗