bluuebunny/crossref_metadata_2025 huggingface dataset:
Anomalies, the Dark Universe and Matter-Antimatter asymmetry
Authors: Mavromatos Nick E.
Published: June 2023

I review a (3+1)-dimensional, string-inspired cosmological model with gravitational anomalies (of Chern-Simons (CS) type) at early epochs, and a totally-antisymmetric torsion, dual to a massless axion-like field (“gravitational axion”), which couples to the CS term. Under appropriate conditions, primordial gravitational waves can condense, leading to a condensate of the CS anomaly term. As a consequence, one obtains inflation in this theory, of running-vacuum-model (RVM) type, without the need for external inflatons. At the end of the inflationary era, chiral fermionic matter is generated, whose gravitational anomalies cancel the primordial ones. On the other hand, chiral anomalies of gauge type, which are also generated by the chiral matter, remain present during the post-inflationary epochs and become responsible for the generation of a non-perturbative mass for the torsion-related gravitational axion, which, in this way, might play the rôle of a Dark Matter component of geometrical origin. Moreover, in this model, stringy non-perturbative effects during the RVM inflationary phase generate periodic structures for the potential of axion-like particles that arise due to compactification, and co-exist with the gravitational axions. Such periodic potential modulations may lead to an enhanced production of primordial black holes during inflation, which in turn affects the profile of the generated gravitational waves during the radiation era, with potentially observable consequences. This model also entails an unconventional mechanism for Leptogenesis, due to Lorentz-violating backgrounds of the gravitational axions that are generated during inflation, as a consequence of the anomaly condensates, and remain undiluted in the radiation era.
Beyond semiclassical time: dynamics in quantum cosmology
Authors: Chataignier Leonardo
Published: June 2023

We review two approaches to the definition of the Hilbert space and evolution in mechanical theories with local time-reparametrization invariance, which are often used as toy models of quantum gravity. The first approach is based on the definition of invariant relational observables, whereas the second formalism consists of a perturbative construction of the Hilbert space and a weak-coupling expansion of the Hamiltonian constraint, which is frequently performed as part of the Born-Oppenheimer treatment in quantum cosmology. We discuss in which sense both approaches exhibit an inner product that is gauge-fixed via an operator version of the usual Faddeev-Popov procedure, and, in the second approach, how the unitarity of the effective Schrödinger evolution is established perturbatively. We note that a conditional probability interpretation of the physical states is possible, so that both formalisms are examples of quantum mechanics with a relational dynamics.
Time-loops to spot torsion on bidimensional Dirac materials with dislocations
Authors: Iorio Alfredo , Pais Pablo
Published: June 2023

Assuming that, with some care, dislocations could be meaningfully described by torsion, we propose here a scenario based on an previously unexplored role of time in the low-energy Dirac field theory description of two-space-dimensional Dirac materials. Our approach is based on the realization of an exotic time-loop, that could be realized by an oscillating particle-hole pairs, to overcome well-known geometrical obstructions due to the luck of a spatial third dimension. General symmetry considerations allow to conclude that the effects we are looking for can only be seen if we move to the nonlinear response regime.
A metric for Planck Stars derived from Gravity in Asymptotic Safety
Authors: Scardigli Fabio , Lambiase Gaetano
Published: June 2023

The Asymptotically Safe Gravity (ASG) framework suggests a “running” Newtonian coupling constant, which depends on two free parameters

ω

∼

and γ. The new black hole metrics inferred from such a “running” gravitational constant naturally match with a Schwarzschild metric at large radial coordinate. By further imposing the matching with the Donoghue quantum corrections to the Schwarzschild field, we find a negative value of the

ω

∼

parameter, and this leads to a not yet explored black hole metric, which surprisingly turns out to describe the so-called Planck stars.
A brief tour of gauge CPT
Authors: Koltko K
Published: June 2023

We outline the gauge theory of CPT transformations. Gauge CPT provides an alternative to the dark matter hypothesis by unveiling a natural extension of general relativity. Additionally, the new dynamical degrees of freedom revealed by gauge CPT should be essential for any approach to quantum gravity. Even though it may seem absurd to entertain the notion of gauging a discrete symmetry because there are no continuous parameters, we show otherwise via a “back door”.
Complete complementarity relations for three-flavor neutrino oscillations
Authors: Bittencourt V A S V , Blasone M , Siena S De , Matrella C
Published: June 2023

We study quantum correlations encoded in a three-flavor neutrino system by using complete complementarity relations (CCR). Due to the presence of local coherence in two-flavor subsystems, the CCR has an additional contribution not present in the two flavor mixing case. We investigate such coherence for the three possible bipartite subsystems of the global state both for an electron and a muon neutrino system.
Low-cost, open-hardware shadow band system for diffuse irradiance measurements
Authors: Quispe G , Pérez J , Conde L , Carhuavilca A , Berastain A , García M , Töfflinger J A
Published: June 2023

In this work, we present the design, implementation, and test of a low-cost, open-hardware shadow band system that enables a pyranometer to measure global and diffuse irradiance. This system was implemented in Lima, Peru, and experimentally tested by contrasting it with a commercial reference system consisting of two pyranometers, one blocked by a shadow ring. The developed shadow band system automatically opens and closes to measure the global and diffuse irradiance consecutively, respectively, without requiring regular, manual adjustments of the shadow ring position as in the reference system. Thus, it potentially saves costs on equipment to characterize de irradiance components. Initial measurements in Lima indicate 100% and at least 23% of diffuse irradiance under cloudy and clear sky conditions, respectively.
Optimization and characterization of synthetic crude obtained from expanded polystyrene waste
Authors: Ramos W , Zamudio V , Villegas E , Palacios A , Pretell V
Published: June 2023

This research seeks to optimize and characterize the liquid product obtained from the waste expanded polystyrene (EPS) pyrolysis. Statistical analysis of the experimental results of EPS pyrolysis was developed. A maximum yield of the liquid product was obtained at a temperature of 550 °C and an average particle size of 7.5 mm. Likewise, the total sulfur content, ASTM distillation, API Gravity and density were determined for the liquid product obtained under optimal conditions. Other physicochemical properties were estimated, concluding that the liquid product is similar to synthetic crude.
Influence of the temperature of a white LED on its lighting characteristics
Authors: Quispe M R , Oscco F M A , Horn M J , Gómez M M
Published: June 2023

The influence of the temperature of two white LEDs, a good brand and one of unknown brand, on their characteristic curves and their light properties was experimentally evaluated in the range from 10 °C to 95 °C. The measurements show that the luminous efficacy decreases with increasing temperature, specially of the LED of unknown brand. In addition, a small redshift could be observed of the blue peak of their respective spectra, as well as changes in their correlated color temperatures (CCT).
Preliminary Study of Slagging Fouling and Corrosion Coal Co-Firing with Biomass and Synthetic Waste in Drop Tube Furnace
Authors: Karuana F , Nainggolan L M , Ruhiyat A S , Putra H P , Listijorini E , Hariana
Published: June 2023

Synthetic waste may be used as biomass fuel in a coal-fired power plant (CFPP) or as part of a coal mixture via co-firing. Differences in characteristics can cause problems during combustion, especially in plastic waste containing high alkali and chlorine content. The purpose of this research is to analyze the features of coal combustion with biomass and synthetic waste mixture to assess the effects of combustion. Combustion is conducted in a drop tube furnace (DTF) by analyzing the possibility of slagging, fouling and corrosion of the ash produced from each fuel. From the results of burning coal, no ashes stuck, only a trace of dust, in contrast to the results of burning coal with a mixture of 25% biomass and synthetic waste which produces a dark colour and has a tendency to stick to the probe. The change in the texture of the probe surface indicates that burning coal with a 25% mixture of biomass and synthetic waste is an unsafe composition for slagging, fouling, and corrosion.
Identification and analysis of municipal solid waste pre-treatment to improve waste quality for waste-to-energy facility
Authors: Wahyono S , Sahwan F L , Suryanto F , Suprapto  , Prasetyadi  , Pratama R A , Parlina I , Tilottama R D , Sarkiwan  , Diyono  , Arreza G
Published: June 2023

The quality of municipal solid waste affects the performance of incinerator waste-to-energy plants. This study aimed to identify and analyze the pre-treatment process for municipal solid waste in order to improve the quality of waste which will be used as feedstock to a waste-to-energy plant using pre-treatment equipment in terms of process rate, mass balance, and waste quality before and after the pre-treatment. The municipal solid waste came from resident housing in DKI Jakarta and the pre-treatment facilities used consisted of a feeder conveyor, trommel screen, and sorting conveyor, as well as excavators. The research was done quantitatively. The results of this study show that the pre-treatment process assisted by 17 workers in one work shift (7 hours) can handle 39.06 tons of waste. The waste consisted of 10.5% bulky waste, 27.6% materials smaller than 5 cm, 1.5% recyclable materials (metal, glass, and plastic), and 59.5% combustible materials. The combustible material was relatively free from bulky material, inert material, and hazardous material. Its calorific value increased from 6.61 MJ/kg to 8.80 MJ/kg. It is concluded that waste after pre-treated had good quality as a feedstock of incinerator waste-to-energy.
Denitrification of ammonium nitrate industrial wastewater using sulfur and limestone packed bioreactor
Authors: Nugroho R , Ikbal  , Said N I , Hasanuddin
Published: June 2023

One of the ammonium nitrate industries in Indonesia, PT.X, is located in West Java. This industry produces wastewater containing 1890 mg/L ammonia-nitrogen, 1800 mg/L nitrate-nitrogen, and 51 mg/L nitrite-nitrogen. In industrial treatment, this wastewater is treated using activated sludge nitrification and anoxic denitrification by adding carbon sources such as methanol or glucose. Denitrification process using autotrophic bacteria is applied in wastewater treatment as an alternative method for reducing the cost of wastewater treatment. The bacteria can grow and develop on elemental sulfur. This paper presents the results of industrial wastewater treatment of ammonium nitrate by two processes: nitrification using activated sludge and denitrification using sulfur and limestone packed-bed bioreactors. Sulfur was used as an electron donor, reducing nitrate to nitrogen gas with sulfate as a by-product. Limestone was used as a material that could minimize the pH decrease caused by the sulfate formation. The residence time applied in this study was from 1 to 4 days; the longer the residence time, the higher the efficiency of nitrogen nitrate reduction. The highest efficiency of nitrate-nitrogen reduction was 97%, achieved at a residence time of 4 days at the nitrate-nitrogen initial concentration of 2,000 mg/L. The water pH during the denitrification process was in the range of 6.5-7.5, meeting the pH quality standard to be discharged into the environment.
An overview of the circular economy activity for small island wastes and marine debris
Authors: Chandra H , Ismail M F A
Published: June 2023

The national regulation’s scheme to tackle waste and debris in Indonesia’s small islands is by applying the 3R (reduce, reuse, recycle) program. This concept was written in Presidential Regulation no 97 in the year 2017, regarding the National Strategy and Policy of the Management for Household Waste and Similar Waste. Presidential Regulation no. 83/2018 regarding Marine Debris Management also focused on minimizing trash and wastes leaked into the marine water due to anthropogenic activities. The term circular economy has grown significantly since Boulding initiated it in 1966 to countermeasure pollution problems. This paper presents the reality of waste management that occurs in small islands and recommendations for sustainable management according to the circular economy concept. The methodology for this paper was by studying regulations in Indonesia, reviewing circular economy literature, and surveying the reality of waste management implementation in small islands in Kepulauan Seribu, Karimun Jawa, and Wakatobi. The results of the study provide a surprising reality but are common in small islands. Non-organic and solid waste that has no economic value (to be recycled) is used as reclamation material. Economical waste for recycling is managed by a waste bank organization. Organic waste is made into compost or burned in an incinerator that is still functioning. The waste residue on the island is then transported using a garbage transport ship (specifically for the Kepulauan Seribu). For the Karimun Jawa Islands, residual waste is only collected at the temporary dumping area (TPS) in the form of a landfill. Similarly, what happened in the Wakatobi Islands, the residual waste was piled up at the TPS. The implementation of a circular economy in small islands achieves only 2R (reuse and recycle) activities of the 7Rs (redesign, reduce, reuse, repair, refurbish, recycle, and recover). Based on the observation of activities of commercial organizations or communities, the status for implementing a fully circular economy on the small islands is a long journey ahead.
Production of bio-briquettes from pineapple peels and sewage sludge as an alternative renewable energy
Authors: Ariani I K , Anifah E M , Sholikah U , Banaget C K , Maharani V G S
Published: June 2023

The need to investigate an eco-friendly and renewable alternative energy source has been prompted by issues relating to the depletion of conventional fuel resources. One of the best green energy alternatives is bioenergy, which also encourages the sustainable use of agricultural waste. This study was carried out to investigate the utilization of pineapple peels for bio-briquette production. This study aimed to determine the characterization of bio-briquette by using different variations in the composition of sewage sludge, pineapple peels, and adhesive types, and to investigate the effect of different adhesive types on briquette characteristics. This research used rejected papaya, cow dung, and starch as the adhesive. The sludge, peels, and adhesives were blended in the ratios of (90:0:10); (70:20:10); (60:30:10); (30:60:10); (20:70:10); and (0:90:10). The result shows that the optimum briquettes were produced from (0:90:10) composition which was 0% sludge, 90% peel, and 10% starch. These briquettes with (0:90:10) composition had a water content of 5%, ash content of 11%, volatile matter of 13%, fixed carbon of 76%, and calorific value of 4,753.99 Cal/g. Calorific values increased as the composition of pineapple peels increased. Moreover, briquette with starch as the adhesive had better physical properties compared to adhesive from rejected papaya and cow dung.
The evaluation of the used diapers recycling process in Bank Sampah Bersinar
Authors: Indriati L , Wattimena R B I , Febriyanti S R , Rostika I , Syamsudin  , Aini M N , Setiawan Y
Published: June 2023

Disposal of used diapers causes environmental pollution problems. Bank Sampah Bersinar, which is located in Bale Endah, Kabupaten Bandung, West Java Province, Indonesia, has made an effort to recycle used diapers and has been operating since 2021 with a capacity of around 5 tonnes of used diapers per month. The process is started by shredding the used diapers and separating the plastic fraction. The fibre and super absorbent polymer (SAP) slurry are then cooked at about 85 °C and squeezed to separate the SAP gel. The fibre resting in the laundry bag is washed and then sun-dried. The performance of the process has been evaluated and reported in this paper. The recycling efficiency of fibre and plastic was around 1.12% and 31.9%, respectively. The highest loss occurred in the shredder, i.e., about 51% of the material was left in the bottom of the shredder. Both recycled fibre and plastic fractions still contained contaminants. The recycled plastic fraction was difficult to dry since it was contaminated by SAP gel. Three washing methods of recycled plastic have been tried. The recycled plastic fraction with 6–10% of moisture was obtained by using the counter-current washing system. About 73% of recycled fibre was categorised as long fibres, longer than 2 mm. However, the fibre fraction still contained plastic flakes contaminants. The cooking process at 180 °C reduced the number of microorganisms in the fibre fraction effectively. The recycling process still needs to be improved, especially to reduce material loss and get cleaner fibre and plastic fractions.
Palm oil mill effluent (POME) treatment using a combined anaerobic-microalgae down-flow hanging sponge (DHS) reactor
Authors: Almira K R , Shoiful A , Hasiany S , Hartaja D R K , Ardiana C , Nugroho R , Noorain R
Published: June 2023

Palm oil mill effluent (POME) generated from the production of palm oil contains organic and inorganic contaminants that can be a nutrient source for microorganisms such as bacteria, fungi, and microalgae. In this study, POME was treated using a combined anaerobic (R1) and microalgae (R2) in down-flow hanging sponge (DHS) reactor. Chlorella pyrenoidosa was immobilized in sponge carriers of R2 and LED lights were used for 12 hours per day to support microalgae growth. The DHS reactors were continuously operated for 165 days in three phases with different COD loading rates, namely 3, 6, and 12 kg-COD/m³·day in Phase 1, Phase 2, and Phase 3, respectively. The hydraulic retention time (HRT) was set at 46 min and 52 min in R1 and R2, respectively. The highest COD removal rate was achieved at 6.93 kg-COD/m³·day and 4.85 kg-COD/m³·day in R1 and R2, respectively. In addition, maximum phosphate removal was 68% in both reactors. Increased concentration of nitrate in R-2 indicated that nitrification may occur in the reactor. The pH of R1 effluent was relatively stable at neutral conditions, while the pH value of R2 effluent slightly increased. Based on visual observation, bacteria biofilm also grew in the microalgae reactor (R2). Synergistic bacteria-microalgae may play an important role in pollutant removal. The results of this study show that a combined anaerobic and microalgae DHS reactor can be used as an alternative for POME treatment because they have a shorter HRT and can be applied in a small area.
Assessment of Soil Vulnerability Index for surface runoff in Kawal watershed, Bintan island
Authors: Mulyono A , Djuwansah M R , Narulita I , Putra R D , Citraresmini A , Flatian A N , Wahyudin  , Amar
Published: June 2023

The quantity of transformed land cleared after deforestation in the basin demonstrates the severity of soil erosion on Bintan Island. Deposition of eroded material causes eutrophication, blockage, and silting of channels and water bodies, as well as flooding in lowlands and coasts. Heavy rainfall and sparse cover of vegetation ravaged the structure of soil, further preventing it from storing and absorbing water, which increased surface runoff and had an impact on rising erosion rates. The goal of this study was to evaluate the vulnerability class of surface runoff using SVI. The SVI class is based on slope extracted from the digital elevation model, hydrologic soil group, and soil erodibility. The results of the SVI classification for mapping surface runoff susceptibility resulted in areas with low criteria of 7% (664 ha), medium 14% (1,229 ha) and high 79% (7,069 ha). The major influences on the high vulnerability of surface runoff in the Kawal watershed on Bintan island appeared to be rainfall, soil type, land use, and slope gradient.
Mercury Determination in Fish Using Cold Vapour-Atomic Absorption Spectrometry (CV-AAS) with Sodium Borohydride (NaBH4) as the Reductor
Authors: Koesmawati T A , Febrianti F , Halim R , Fitria N , Tanuwidjaja S , Rohman O , Syamsudin A
Published: June 2023

Marine fish can potentially accumulate heavy metal pollutants, such as mercury, from anthropogenic activities that can harm people who consume it. Marine fishes like Bandeng fish (Chanos chanos), Banjar fish (Rastrelliger kanagurta), Bawal Hitam fish (Parastromateus niger), Selar Kuning fish (Atule mate), Tenggiri fish (Scomberomorini), and Tuna fish (Thunnini) are consumed a lot by people in Bandung City. All these fish were analyzed using the CV-AAS method with the United States – Environment Protection Agency (USEPA, 2006), and the reducing agent was replaced by stannous (II) chloride with sodium borohydride. Variations in the sample preparation process include drying the sample using an oven and freeze dryer. SEM-EDX in the frozen-dried samples shows that the fibbers’ morphology is intact, while the fibbers are damaged in the hot-dried samples. During characterization using FTIR, there is a slight shift in wave number. The mercury concentrations obtained from every sample were below 0.5 mg/kg based on the Indonesian National Standard (SNI) 2009 standard for total mercury in fish. Therefore, it can be concluded that the samples are safe to be consumed. Validation methods showed that 0.3% sodium borohydride as the reductor can be used to analyze mercury and replace stannous (II)chloride. However, further studies are needed to determine the optimal concentration of sodium borohydride (NaBH4) in the marine fish samples as a reduction agent.
Atmospheric concentrations of polybrominated diphenyl ethers (PBDEs) in passive air sampler from Batam Island, Indonesia
Authors: Sulistia S , Ilyas M , Suciati F , Kurniawan B , Isobe T , Kunisue T , Tanabe S , Sudaryanto A
Published: June 2023

Air contamination by semi volatile organic compounds including toxic polybrominated diphenyl ethers (PBDEs) has been a matter of global concern due to the important atmospheric transportation in contribution to their widely distribution in environment. This study aims at elucidating the levels and spatial distribution of PBDEs in the atmosphere derived from polyurethane foam passive air sampler (PUF-PAS) and identify potential sources in Batam Island. Fifteen PUF-PAS were deployed in various locations representing different background activities. After deployment around 2.5 months, PUFs were analyzed for forty-two PBDEs congeners from mono- to deca-BDE congeners using gas chromatography with mass spectrometry. PBDEs were widely detected ranging 7.2 – 2900 pg/m3. Significant high concentrations of PBDEs were found at public service areas than offices, residential and remote areas (p<0.05). In particular, high concentration was found in Marina Tanjung Riau (2900 pg/m3), whereas other locations were much lower including electronic shop (50 pg/m3), dumping site area (7.2-15 pg/m3), which indicating specific emission sources according to location. The PBDEs profiles are predominated by BDE-209 congener on average 81% (36-100) while other congeners were lower. This suggest that the presence of PBDEs in Batam Island is mainly due to the commercial formulation of Deca-BDE, of which consistent with its high consumption in Asia.
Modeling and mapping the environmental impact of debris flow hazard on alluvial fans for sustainable development in Bangga and Poi Villages, Sigi, Central Sulawesi
Authors: Putra M H Z , Sarah D , Sadisun I A , Soebowo E , Aulia A N , Sukristiyanti
Published: June 2023

On September 28, 2018, an Mw 7.5 Palu earthquake triggered massive landslides upstream, followed by 24 debris flood events that spread to 15 villages in Sigi from September 2018 to December 2021. Debris flow and flash floods on alluvial fans inundated lowland communities, causing severe property destruction and structural damage to bridges and roadways and resulting in an estimated 900 damaged houses. Understanding their historical occurrence is essential to sustainable fan development and minimizing their threat to infrastructure and human life due to their severe geohazard potential. Poi and Bangga Villages were affected by the disastrous debris flood in Sigi Regency, Central Sulawesi. This study aimed to create a landslide inventory map, a back-analysis model, and a damage and loss assessment (DaLAs) to evaluate the potential hazard and environmental impacts of debris flow on Sigi’s alluvial fans. The result of landslide mapping showed more than 400 mapped landslides within Bangga Village in various sizes and a massive landslide within Poi Village were digitized. Then, the back-analysis model overpredicted flow direction due to vegetation, infrastructure, and road information not covered by the digital elevation model (DEM). Finally, DaLAs shows the losses caused by damaged buildings were estimated at around 65.7 and 7.4 billion rupiah in Bangga and Poi Villages, respectively.
Spatial distribution of atmospheric polychlorinated biphenyls (PCBs) in Jakarta Great Area using passive air sampler
Authors: Sudaryanto A , Ilyas M , Wahyono I B , Aviantara D S , Efadeswarni  , Takahashi S , Isobe T , Tanabe S , Kunisue T
Published: June 2023

Assessing of air contamination by persistent organic pollutants (POPs) has been a matter of global concern due to the atmosphere as key transport route for these pollutants. Furthermore, polyurethane foam passive air sampler (PUF-PAS) has been used as one of proved methods for air monitoring of POPs. The objectives of this study are to elucidate the levels and distribution of polychlorinated biphenyls (PCBs) in atmosphere of Jakarta and surrounding areas in respect to the different in concentration levels, possible origin of their sources and magnitude of their contamination. Sixty-two PCB congeners were quantified in PUF disk from PAS deployed at nine locations representing different background area by using a gas chromatography equipped with mass spectrometry detector. PCBs were detected in all PUF with concentrations varied according to location (ranged 29 – 220 pg/m3), indicating specific location source of PCBs. The highest concentration of PCBs was found in air of dumpsite and were followed by industrial>urban>sub-urban areas, suggesting that dumpsite and industrial areas are as emission sources of these compounds. The concentration levels of PCBs were generally similar to some other countries in Africa and South America but lower than those of industrial countries worldwide. The lighter PCB congeners were the predominant compounds, which correspond to specific technical mixtures and their volatile properties.
Estimating baseline CO2 emission from waste collection and transport activity to TPST Bantargebang, Jakarta
Authors: Setiaji R , Sunarya A F S , Adhi R P , Pratama R A
Published: June 2023

Municipal solid waste is one of the fundamental problems in DKI Jakarta Province. The increasing population and various human activities had a direct effect on this issue. TPST Bantargebang served and treated all waste in DKI Jakarta Province, and the volume of waste generation reached 7,702 tons per day in 2019. Despite the waste generation, waste collection and transport are becoming emerging issues. The level of service by the Environmental Agency of DKI Jakarta Province is planned to reach 98% in 2025. Dump and waste trucks come and go in the long queue every day around TPST Bantargebang. This study estimated CO2 emissions from waste collection and transport activity using daily logbook data, fleet data, and spatial analysis. This study assigned the source point as a temporary disposal site in each subdistrict. It showed that the total vehicle kilometer traveled (VKT) reached 71,990.72 km/day, which collected and transported 5,897.67 tons of waste/day from 196 subdistricts. The need for fuel consumption reached 31,989.17 liters of bio-solar per day. The baseline of CO2 emission reached 70.805 tCO2 per day by multiplying the bio-solar emission factor and total fuel consumption. The CO2 emission per ton of waste transported reached 12 kg CO2 per day and the CO2 emission per kilometer of waste transported reached 0.98 kg CO2 per day.
Effect of the implementation of community activity restriction policies during the COVID-19 pandemic on air quality
Authors: Ihsan I M , Ma’rufatin A , Salim M A , Rifai A , Ikhsan I N , Anjani R , Nishihashi M , Hashimoto S , Mukai H , Suwedi N
Published: June 2023

The Indonesian government implemented restrictions on social activities to reduce the spread of the COVID-19 virus. Limiting activities reduced transportation and industrial activities, so it was suspected that it could affect air quality in Serpong. This research aimed to analyze PM2.5and PM10 concentrations before, during, and easing of the restrictions on COVID-19. In addition, this research also examined the correlation between pollutant concentration levels and precipitation. PM2.5and PM10 concentrations and precipitation data were obtained from real-time and continuous measurements from January 2020 to August 2022. The analysis used was descriptive, comparison, and correlation. The comparison analysis to determine particulate concentration before activity restrictions, first Large-Scale Social Restrictions (LSSR-1), LSSR-New normal, LSSR-Transition period, Emergency Community Activities Restriction Enforcement (Emergency CARE), and easing of COVID-19 restrictions. The analysis shows that the average concentrations of PM2.5and PM10 during the measurement period were about 33 μg/m3and 56 μg/m3, respectively. Comparative analysis indicates differences in PM2.5concentrations between before the activity restrictions were imposed and LSSR-1, LSSR-New Normal, Emergency CARE, and the easing of COVID-19 restrictions. In addition, there was a difference in the average PM10 concentration between before activity restrictions and LSSR-New normal and emergency CARE. Correlation analysis shows a weak relationship between precipitation and PM concentrations in the representative wet and dry months.
Study of Total Dissolved Solids (TDS) and Total Suspended Solids (TSS) in Estuaries in Banten Bay Indonesia
Authors: Sugiarti  , Rohaningsih D , Aisyah S
Published: June 2023

The estuaries of Banten Bay have sandy sediment, and their main activity is fisheries. In order to maintain fishery productivity, good water quality is required. The sandy sediment in this location can affect water conditions at the point of the residue content. This study aims to reveal solids content in the estuaries of Banten Bay. A survey was conducted in four estuaries, namely Karangantu, Wadas, Cengkok, and Pamong. TDS were measured in situ in April and October 2021. TSS was analyzed in May, July, and October 2013, as well as in April and October 2021. Other physical and chemical parameters were analyzed in the laboratory or in situ. The results were compared with the standard for sea aquatic biota. Furthermore, the regression method was used to determine the correlation of TSS and TDS with other parameters. The physical and chemical parameters that affect TDS and TSS were analyzed using Principal Component Analysis (PCA). The results show that TSS correlated with Oxidative Reductive Potential (ORP) and turbidity. PCA showed that TSS correlated with TDS, nitrate, ammonium, ORP, water depth, and water current. Although TSS exceeded the threshold, sufficient dissolved oxygen and higher nutrient still maintained water quality for fisheries in four estuaries.
The geo-environmental influence on hydrogeochemical conditions in the Tanjaknangsi volcanic region
Authors: Maria R , Rusydi A F , Naily W , Iskandarsyah T Y W M , Suganda B R , Hendarmawan H
Published: June 2023

Groundwater in volcanic areas flows from the recharge to the discharge, and dissolving rock minerals undergo hydrochemical changes. Anthropogenic influences in the form of increasing built-up land and plantation activities in upstream areas raise concerns about changes in groundwater hydrochemistry. Hydrogeochemical and environmental characterization of groundwater in volcanic regions is essential to trace the rock-water interaction. This study aimed to determine the geo-environmental influence on the hydrogeochemical conditions in Tanjaknangsi volcanic areas. The methods used were statistical analysis, bivariate analysis, and Piper diagram. During the dry season, 16 groundwater samples were taken, consisting of five dug wells, nine drilled wells, and two springs. The hydrogeochemical process of major ions in groundwater volcanic regions is characterized by the weathering of silica. The concentrations of cations were Ca2+> Na+> K+> Mg2+, while the anion were HCO3−> Cl−> SO4−. The correlation analysis shows that Ca2+, Mg2+, and Na+cations strongly correlated with the HCO3−anion. Hierarchical dendrogram analysis shows groundwater was influenced by the rock-water interaction and anthropogenic influences; the piper diagram shows the dominant hydrogeochemical facies in the study area were CaCl, CaMgCl, CaMgHCO3, and NaHCO3. Groundwater in the upstream area was dominated and influenced by the groundwater-rock interaction, while anthropogenic factors influenced groundwater in the downstream area. Residues of anthropogenic activities such as agriculture, plantations, and livestock will increase the levels of NH4-N, Cl−and SO42-ions.
Spatial distribution of carbon dioxide (CO2) fluxes in the Sunda Strait and west of Sumatra waters
Authors: Wahyono I B , Aldrian E , Soepardjo A H
Published: June 2023

Carbon dioxide (CO2) is one of the main global warming gases which cause global climate changes, droughts, forest fires, sea level rise, and flooding. Natural CO2 sinks are the mainland, oceans, and atmosphere. Indonesian waters have the potential to absorb CO2 due to their high primary productivity. This study aimed to understand the variability of CO2 in order to determine whether Indonesian waters act as carbon sources or carbon sinks and fill the CO2 data gaps. The field survey was conducted at the Sunda Strait and west Sumatra waters during February–April 2010, using RV Baruna Jaya III. The Sunda Strait has a role as a carbon source, whereas the west of Sumatra waters as carbon sinks. The partial pressure of CO2 is more influenced by the pH. The average net flux of CO2 in the Sunda strait was 841.603 mol CO2cm−2day−1, which shows the release of CO2 from the ocean into the atmosphere occurs in this region. On the other hand, the average net flux of CO2 in the west of Sumatra was -945.292 mol CO2cm−2day−1, which shows the absorption of CO2 by the ocean occurs in the region.
Barrier analysis to leverage the climate change mitigation-adaptation implementation action in mangrove forest and its surrounding community villages
Authors: Winanti W S , Sudinda T W , Oktivia R , Ihsan I M , Ikhwanuddin M , Amru K , Anjani R , Aryantie M H
Published: June 2023

In the Nationally Determined Contribution document (NDC), Indonesia has a target for reducing greenhouse gas emissions of 29% on its own capability and 41% with international assistance by 2030, and plans to initiate action to achieve net zero emissions by 2050 as outlined in the Long-term Strategy for Low Carbon and Climate Resilience (LTS-LCCR) 2050 document. Mangrove forest ecosystems can absorb carbon emissions 4-5 times greater than terrestrial forests, are used as one of source to achieve Indonesia’s NDC and LTS-LCCR targets. Mangrove forest is also as a barrier to coastal abrasion. Mangrove forests can be damaged by natural cause and also due to human activities. Socialization of its importance and improving the economic community welfare around mangrove forests are important factors to prevent damage and maintain its sustainability. The improving economic community efforts can be carried out by applying mitigation-adaptation actions/economic activities of the community. This activity aims to analyse the barrier and challenges in preserving and restoring, as well as rehabilitating the mangrove forests ecosystem in the Indramayu and Brebes regencies. The data obtained from field surveys while the methodology for barrier analysis refers to the methodology that has been used in the preparation of Indonesia’s Climate Change mitigation and adaptation Technology Action Plans (TAPs) documents. The barrier analysis includes regulatory/policy, technical, financial, coordination, and social and/or institutional barrier aspects. These barriers have been analysed, mapped and identified, then causal relations of the barriers have been carried out and identified. Then the cross-cutting issued/integrated the measures of both issues and prioritized the cross-cutting issued can be determined.
The growth of mercury-resistant bacterial consortium at different levels of pH, temperature, and C:N ratio
Authors: Amandita F Y , Efadeswarni  , Ikhwani A Z N , Idris  , Sugiharto A , Fatma Y S , Alfiansah Y R , Sudiana I M
Published: June 2023

The study was conducted to investigate the growth of mercury-resistant bacterial consortium under the influence of different pHs, temperatures, and C:N ratios, as a part of mercury bioremediation research. The consortium consisted of five bacterial isolates selected due to their resistance to HgCl2 up to 100 ppm and was proven to effectively reduce mercury from the culture media. Consortium suspension was inoculated into two sets of media: 1) Tryptic soy broth (TSB) with pHs of 4.8, 6.1, 8.5, and 9.7; 2) Mineral salt with the addition of glucose and peptone to create C:N ratios of 20:1, 30:1, and 40:1 while the pH was set to 7.4. For comparison, a solution containing mercury-contaminated soil was added to the same set of media and regarded as a microbial community. The growth curves show that the bacterial consortium tended to grow better compared to the microbial community, especially in the TSB medium at incubation temperatures of 20 and 35 °C. In the same medium at a temperature of 45 °C, the growth of both consortium and community under high pHs (8.5 and 9.7) was higher than the one under lower pHs (4.8 and 6.1). Meanwhile, in the mineral salt medium, the influence of the inoculant was not remarkable except under an incubation temperature of 35 °C. Moreover, the C:N ratio did not affect the growth of either the bacterial consortium or the microbial community (p > 0.05). The variance analysis also indicated that the growths were significantly different only when the pH was 4.8.
Optimization of mechanical properties of carrageenan-based bioplastic as food packaging
Authors: Genecya G , Adhika D R , Widayani  , Wungu T D K
Published: June 2023

Several types of plastic materials are widely used in food packaging because it has good mechanical and physical properties. However, the types of plastic used in food packaging, such as polyethylene (PE), polypropylene (PP), and polycarbonate (PC), are petroleum-based plastic that is not renewable, not biodegradable, and causes environmental pollution. One option to overcome this problem is to make bioplastic using renewable sources, one of which is carrageenan. Carrageenan is a polysaccharide used in bioplastic synthesis, but it has shortcomings in terms of mechanical properties. Thereby it needs additional supporting materials to improve its mechanical properties. This study aims to obtain optimal mechanical properties such as tensile strength, elongation, and modulus of elasticity. We optimized two variables in this study: glycerol concentration (1, 2, 3, 4, and 5%) and montmorillonite concentration (10, 20, and 30%). Optimization was carried out in two stages; the first stage was the optimization of glycerol concentrations, and the second stage was the optimization of montmorillonite concentrations. The optimum condition was obtained at 3% (v/v) glycerol and 20% (w/w) montmorillonite which gives a tensile strength value of 3.43 MPa, elongation of 47.01%, and Young Modulus of 7.31 MPa. Based on these optimization results, carrageenan-based bioplastic, especially on %EAB value, are comparable with other commercial plastic for food packaging.
Antibacterial potential of zinc oxide nanoparticles derived from pineapple peel aqueous extract
Authors: Nida V , Saraswaty V , Nissa R C , Endah E S , Ratnaningrum D , Risdian C , Setiyanto H
Published: June 2023

Pineapple peel waste contains antioxidant molecules. This paper describes a facile, efficient, and environmentally friendly approach for synthesizing ZnO nanoparticles using pineapple peel aqueous extract. This method aims to reduce the use of harmful chemicals in producing ZnO nanoparticles using zinc nitrate as a salt precursor and evaluating their antibacterial. Pineapple peel aqueous extract was obtained by macerating pineapple peel powder in distilled water. Engaging Zn(NO3)2, pineapple peel aqueous extract, and NaOH, ZnO NPs were successfully prepared by biosynthesis. X-ray diffraction (XRD) analysis and Fourier transform infrared (FTIR) spectroscopy was utilized to confirm the formation of ZnO NPs, while scanning electron microscopy (SEM) was employed to see the morphology and size distribution of nanoparticles. The antibacterial activity of pineapple peel extract-ZnO nanoparticles (pp-ZnO NPs) against Gram-positive and Gram-negative bacteria was evaluated by an agar disc diffusion method. The SEM images showed that by applying pineapple peel aqueous extract, the pp-ZnO with an average size below 100 nm with a mixture of flakes and rod-like shapes were obtained. The XRD pattern confirmed the wurtzite phase of ZnO, while antibacterial assay results showed that the pp-ZnO actively inhibited B. subtilis and E.coli. at concentrations of 5 and 10 wt%. Therefore, phyto-assisted synthesis mediated by pineapple peel wastes is a promising green approach to preparing ZnO nanoparticles.
Coconut coir utilization as a catalyst precursor in the transesterification process of used cooking oil into cocodiesel
Authors: Afghani F A , Sofyan M I , Agustiani T , Sulistia S , Mansur D , Sampora Y , Yubaidah S , Manawan M T , Hafizah M A E , Piton J K
Published: June 2023

This study aims to make a catalyst from biomass waste in the form of coconut coir and apply it to the transesterification process of cocodiesel. The raw material for cocodiesel in this study was a coconut-based cooking oil that was also a waste and could pollute the environment. The research method includes cooking oil analysis, the catalyst’s preparation, and the catalyst’s characterization with Brunauer-Emmet-Teller (BET), X-ray fluorescence (XRF), X-ray diffraction (XRD), and Scanning electron microscope (SEM) analysis. The next step was the application of the catalyst in the transesterification reaction. The results showed interesting information, in which the addition of the calcination process increased the catalyst’s surface area and crystallinity ratio. Applying a catalyst in converting used cooking oil to cocodiesel gave 48.5% and 51% yields with densities close to the biodiesel standard.
Quick sterilization of Spirulina powder through dry ozonization for pharmaceutical preparations
Authors: Djayanti S , Rame  , Mukimin A , Nilawati  , Pratista D R
Published: June 2023

Quick sterilization using dry ozonation technology had been developed to destroy total pathogenic microorganism contamination in Spirulina powder effectively. This technology is safe and environmentally friendly, with carbon dioxide (CO2) and water (H2O) as output. Quick sterilization applications are easy and inexpensive but provide results that meet the quality standards of pharmaceutical preparations according to government regulations. This work aimed to perform rapid sterilization and determine the microbial level contamination produced by the ozonation sterilization system. The variables of sterilization time, flow rate, and ozone dose differ in the application of the ozonized sterilization system. The sterilization process through an ozonation reaction is carried out by providing ozone at the flow rate of 1, 2, 3, and 4 liters per minute (LPM) and ozone concentrations of 1, 2, 3, and 4 ppm. Ozone was produced at a rate of 5 gr/hour from an ozone generator with a voltage of 30 kV. 40 gr Spirulina powder in a closed reactor with a volume of <50% (Spirulina/reactor volume) was ozonated at room temperature (27 °C) for 1, 2, 3, and 4 minutes. The optimum operating conditions of Spirulina platensis sterilization were an ozone flow rate of 2 LPM, sterilization time of 2 minutes, and ozone dose of 2 ppm. This system reduces the sterilization time from 60 minutes (UV light) to 2 minutes. This technology is a very attractive and potential choice in the large-scale production of Spirulina powder for pharmaceutical industry applications.
Synthesis and characterization of calcium phosphate (tricalcium phosphate/calcium pyrophosphate) from snail shells (Achatina fulica)
Authors: Ardiansyah A , Saraswaty V , Risdian C
Published: June 2023

Snail (Achatina fulica) is one of the sources of duck fodder commonly used by local breeders to meet protein needs of poultry farms. However, its shells as a by-product are rarely used and just become waste. To overcome this problem, we try to utilize the waste to be used as a source of bioceramic. Snail shells contain a lot of calcium which can be used as a calcium precursor to make bioceramics. One of the bioceramics that has the potential are tricalcium phosphate (TCP) and calcium pyrophosphate (CPP). They are mostly used as material for bone regeneration. It has advantages in terms of biocompatibility and osteoinductivity. In this study, we synthesized and characterized calcium phosphate from snails by coprecipitation method. It was then analyzed using X-Ray fluorescence (XRF), X-Ray diffraction (XRD), fourier transform infrared (FTIR), energy dispersive X-Ray (EDX), and scanning electron microscope (SEM) analysis to see its characteristic. Based on XRF analysis, snail shell (raw material) contains 81.83% of calcium and calcium phosphate mixed bioceramics (TCP and CPP). Average crystal size is 17.00 nm. The surface shape of the formed particles was irregular, and also flux, sphere, and fracture shaped. Nevertheless, interfering compounds were still found, hence a further purification process needs to be conducted.