Cotton pads-derived carbon materials/reduced graphene oxide modified with polypyrrole for electrode of supercapacitors

This study investigates the influence of electropolymerization conditions on the deposition of polypyrrole(PPy)onto cotton-derived carbon fiber(CF)modified with reduced graphene oxide(rGO)for supercapacitors applications using an experimental/theorical approach.The surface modification of CF by rGO and/or by PPy electrodeposited at 10,25 and 50 mV s^(-1) was thoroughly examined physicochemical and electrochemically.Composite electrodes comprising CF-rGo-PPy,synthesized via electropolymerization at 25 mV s^(-1),demonstrated a remarkable increase in capacitance,showcasing~742 F g^(-1) compared to 153 F g^(-1) for CF.SEM,N_(2)-surface area,XPS,and TD-DFT approach revealed that the higher capacitance observed in CF-rGo-PPy electrodes underscores the influence of morphology and charged nitrogen species on the electrochemical performance of these modified electrodes.Notably,this electrode material achieves a specific capacitance retention of~96%of their initial capacitance after 10000 cycles at 0.5 A g^(-1) measured in a two-electrodes cell configuration.This work also discusses the influence of the scan rate used for pyrrole electropolymerization on the pseudocapacitance contribution of PPy and its possible effect on the porosity of the material.These results highlight the importance of appropriate electropolymerization conditions that allow obtaining the synergistic effect between CF,rGO and PPy.

Initial discovery of microplastic pollution in Mnemiopsis leidyi(Ctenophora:Lobata)

The production of plastics has exponentially increased over time such that the observation of microplastics in the oceans has become a major concern given how frequently these particles and marine biota may interact.Microplastics can be ingested by diverse species,including invertebrates,which can lead to physical damage due to their small size and potentially chemical damage related to the ingestion of monomers,polymeric additives,or adsorbed chemicals.This study reports on the first evidence of microplastics in Mnemiopsis leidyi.Microplastics were described by type,quantified,and had their chemical composition identified.In total,328 samples of microplastic(MP)candidates were observed:blue fibers were the most abundant,followed by black,red,and green fibers as well as blue fragments.Three types of microplastics were chemically identified as polyurethane,unplasticized polyvinylchloride,and polyethylene polylauryllactam.Overall,this study demonstrated that Mnemiopsis leidyi have the capacity to incorporate microplastics.Although more studies are needed,Mnemiopsis leidyi is relatively abundant on the Atlantic coast and should be recommended for use as a bioindicator for microplastics.

Evaluation of Early Action Mechanisms in Peru Regarding Preparedness for El Nino

In this article,we provide an impact evaluation of an intervention in Peru regarding preparedness for El Nino impacts in Picsi District of Chiclayo Province in Peru’s northwestern coastal Lambayeque region.This effort involved the provision of special kits that reduce the potential damage to homes as a consequence of rainfall and floods associated with an El Nino-Southern Oscillation event.Information was collected in 2016 when this Forecast-based Financing early action was activated by an El Nino forecast,and after a coastal El Nino actually struck in 2017.This dual database permits us to estimate the impact of the intervention on the damage level of homes by comparing those homes supported by the program with those homes not receiving pilot-program support.This comparison is achieved by using propensity score matching techniques,which identify the most comparable homes to the ones that were supported by the intervention.The main findings of the study suggest a positive impact of the program in terms of its effectiveness in mitigating the damage caused by the 2017 El Ni?o.These results suggest a drop in the scale of house damage(less damage)by around 63%for a home that received the modular kit treatment.When considering other specifications of the model,the decrease in the scale of house damage improves up to approximately 66%.

Mercury levels in human population from a mining district in Western Colombia

A biomonitoring study was carried out to examine the adverse impacts of total mercury in the blood（HgB）, urine（Hg U） and human scalp hair（HgH） on the residents of a mining district in Colombia. Representative biological samples（scalp hair, urine and blood） were collected from volunteered participants（n = 63） to estimate the exposure levels of THg using a Direct mercury analyzer. The geometric mean of THg concentrations in the hair,urine and blood of males were 15.98 μg/g, 23.89 μg/L and 11.29 μg/L respectively, whereas the females presented values of 8.55 μg/g, 5.37 μg/L and 8.80 μg/L. Chronic urinary Hg（HgU）levels observed in male workers（32.53 μg/L） are attributed to their long termed exposures to inorganic and metallic mercury from gold panning activities. On an average, the levels of THg are increasing from blood（10.05 μg/L） to hair（12.27 μg/g） to urine（14.63 μg/L）.Significant positive correlation was found between hair and blood urinary levels in both male and female individuals. Thus the present biomonitoring investigation to evaluate the Hg levels and associated health issues would positively form a framework for further developmental plans and policies in building an ecofriendly ecosystem.