Search results for: Erico R. Carmona
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 19

Search results for: Erico R. Carmona

19 Recovering Copper From Tailing and E-Waste to Create Copper Nanoparticles with Antimicrobial Properties

Authors: Erico R. Carmona, Lucas Hernandez-Saravia, Aliro Villacorta, Felipe Carevic

Abstract:

Tailings and electronic waste (e-waste) are an important source of global contamination. Chile is one of Organisation for Economic Co-operation and Development (OECD) member countries that least recycled this kind of industrial waste, reaching only 3% of the total. Tailings and e-waste recycling offers a valuable tool to minimize the increasing accumulation of waste, supplement the scarcity of some raw materials and to obtain economic benefits through the commercialization of these. It should be noted that this type of industrial waste is an important source of valuable metals, such as copper, which allow generating new business and added value through its transformation into new materials with advanced physical and biological properties. In this sense, the development of nanotechnology has led to the creation of nanomaterials with multiple applications given their unique physicochemical properties. Among others, copper nanoparticles (CuNPs) have gained great interest due to their optical, catalytic, conductive properties, and particularly because of their broad-spectrum antimicrobial activity. There are different synthesis methods of copper nanoparticles; however, green synthesis is one of the most promising methodologies, since it is simple, low-cost, ecological, and generates stable nanoparticles, which makes it a promising methodology for scaling up. Currently, there are few initiatives that involve the development of methods for the recovery and transformation of copper from waste to produce nanoparticles with new properties and better technological benefits. Thus, the objective of this work is to show preliminary data about the develop a sustainable transformation process of tailings and e-waste that allows obtaining a copper-based nanotechnological product with potential antimicrobial applications. For this, samples of tailings and e-waste collected from Tarapacá and Antofagasta region of northern Chile were used to recover copper through efficient, ecological, and low-cost alkaline hydrometallurgical treatments, which to allow obtaining copper with a high degree of purity. On the other hand, the transformation process from recycled copper to a nanomaterial was carried out through a green synthesis approach by using vegetal organic residue extracts that allows obtaining CuNPs following methodologies previously reported by authors. Initial physical characterization with UV-Vis, FTIR, AFM, and TEM methodologies will be reported for CuNPs synthesized.

Keywords: nanomaterials, industrial waste, chile, recycling

Procedia PDF Downloads 80
18 Optimization by Means of Genetic Algorithm of the Equivalent Electrical Circuit Model of Different Order for Li-ion Battery Pack

Authors: V. Pizarro-Carmona, S. Castano-Solis, M. Cortés-Carmona, J. Fraile-Ardanuy, D. Jimenez-Bermejo

Abstract:

The purpose of this article is to optimize the Equivalent Electric Circuit Model (EECM) of different orders to obtain greater precision in the modeling of Li-ion battery packs. Optimization includes considering circuits based on 1RC, 2RC and 3RC networks, with a dependent voltage source and a series resistor. The parameters are obtained experimentally using tests in the time domain and in the frequency domain. Due to the high non-linearity of the behavior of the battery pack, Genetic Algorithm (GA) was used to solve and optimize the parameters of each EECM considered (1RC, 2RC and 3RC). The objective of the estimation is to minimize the mean square error between the measured impedance in the real battery pack and those generated by the simulation of different proposed circuit models. The results have been verified by comparing the Nyquist graphs of the estimation of the complex impedance of the pack. As a result of the optimization, the 2RC and 3RC circuit alternatives are considered as viable to represent the battery behavior. These battery pack models are experimentally validated using a hardware-in-the-loop (HIL) simulation platform that reproduces the well-known New York City cycle (NYCC) and Federal Test Procedure (FTP) driving cycles for electric vehicles. The results show that using GA optimization allows obtaining EECs with 2RC or 3RC networks, with high precision to represent the dynamic behavior of a battery pack in vehicular applications.

Keywords: Li-ion battery packs modeling optimized, EECM, GA, electric vehicle applications

Procedia PDF Downloads 106
17 Synchronization of Semiconductor Laser Networks

Authors: R. M. López-Gutiérrez, L. Cardoza-Avendaño, H. Cervantes-de Ávila, J. A. Michel-Macarty, C. Cruz-Hernández, A. Arellano-Delgado, R. Carmona-Rodríguez

Abstract:

In this paper, synchronization of multiple chaotic semiconductor lasers is achieved by appealing to complex system theory. In particular, we consider dynamical networks composed by semiconductor laser, as interconnected nodes, where the interaction in the networks are defined by coupling the first state of each node. An interesting case is synchronized with master-slave configuration in star topology. Nodes of these networks are modeled for the laser and simulated by Matlab. These results are applicable to private communication.

Keywords: chaotic laser, network, star topology, synchronization

Procedia PDF Downloads 546
16 PTSD in Peacekeepers: A Systematic Review

Authors: Laura Rodrigues Carmona, Maria José Chambel, Vânia Sofia Carvalho

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Background: In peacekeeping operations, military personnel are often exposed to the same traumatic stress factors found during conventional war and may also be subject to the physical risks and psychological stressors associated with posttraumatic stress disorder (PTSD). Objectives: To discuss the prevalence of PTSD among peacekeepers as well as the risks of and protective factors against this disorder and its comorbidities and/or consequences. Methods: A systematic literature search was performed with relevant keywords, and 53 articles were identified for this review. Results and conclusions: Military personnel deployed in peacekeeping operations have a higher prevalence of PTSD than nonmilitary personnel, a prevalence similar to that of military personnel deployed in war situations. Concerning the salient risk factors, the contextual factors are highlighted, and in regard to the protective factors, the individual factors are highlighted. This study thus demonstrates that there are factors in which the role of the military is essential, via both its selection and monitoring of peacekeepers during and after their deployment, to protect deployed personnel’s mental health.

Keywords: peacekeepers, peacekeeping, military, PTSD, post-traumatic stress disorder, posttraumatic stress disorder

Procedia PDF Downloads 62
15 Treatments for Overcoming Dormancy of Leucaena Seeds (Leucaena leucocephala)

Authors: Tiago Valente, Erico Lima, Bruno Deminicis, Andreia Cezario, Wallacy Santos, Fabiane Brito

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Introduction: The Leucaena leucocephala known as leucaena is a perennial legume shrub of subtropical regions in which the forage shows favorable characteristics for livestock production. The objective of the study was to evaluate the influence of methods for overcoming dormancy the seeds of Leucaena leucocephala (Lam.). Materials and Methods: The number of germinated seeds was evaluated daily at the germination criterion radicle protrusion (growth, with about 2 cm long, the emerged seedlings of all). After the counting of the number of germinated seeds daily, the following characteristics were evaluated: Step 1: Germination count which represents the cumulative percentage of germinated seeds on the third day after the start of the test (Germ3); Step 2: Percentage of germinated seeds that correspond to the total percentage of seeds that germinate until the a seventh day after start of the test (Germ7); Step 3: Percentage of germinated seeds that correspond to the total percentage of seeds that germinate until the fifteenth day after start of the test (Germ15);Step 4: Germination speed index (GSI), which was calculated with number of germinated seeds to the nth observation; divided by number of days after sowing. Step 5: Total count of seeds do not germinate after 15 days (NGerm).The seed treatments were: (T1) water at 100 ºC/10 min; (T2) water at 100 ºC/1 min; (T3) Acetone (10 min); (T4) Ethyl alcohol (10 minutes); and (T5) intact seeds (control). Data were analyzed using a completely randomized design with eight replications, and it was adopted the Tukey test at 5% significance level. Results and Discussion: The treatment T1, had the highest speed of germination of seeds GSI, differed (P < 0.05). The T5 treatment (control) was the slowest response, between treatments until the seventh day after the beginning of the test (Germ7), with an amount of 20% accumulation of germinated seeds. The worst result of germination it was T5, with 30% of non-germinated seeds after 15 days of sowing. Acknowledgments: IFGoiano and CNPq (Brazil).

Keywords: acetone, boiling water, germination, seed physiology

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14 Increase of the Nanofiber Degradation Rate Using PCL-PEO and PCL-PVP as a Shell in the Electrospun Core-Shell Nanofibers Using the Needleless Blades

Authors: Matej Buzgo, Erico Himawan, Ksenija JašIna, Aiva Simaite

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Electrospinning is a versatile and efficient technology for producing nanofibers for biomedical applications. One of the most common polymers used for the preparation of nanofibers for regenerative medicine and drug delivery applications is polycaprolactone (PCL). PCL is a biocompatible and bioabsorbable material that can be used to stimulate the regeneration of various tissues. It is also a common material used for the development of drug delivery systems by blending the polymer with small active molecules. However, for many drug delivery applications, e.g. cancer immunotherapy, PCL biodegradation rate that may exceed 9 months is too long, and faster nanofiber dissolution is needed. In this paper, we investigate the dissolution and small molecule release rates of PCL blends with two hydrophilic polymers: polyethylene oxide (PEO) or polyvinylpyrrolidone (PVP). We show that adding hydrophilic polymer to the PCL reduces the water contact angle, increases the dissolution rate, and strengthens the interactions between the hydrophilic drug and polymer matrix that further sustain its release. Finally using this method, we were also able to increase the nanofiber degradation rate when PCL-PEO and PCL-PVP were used as a shell in the electrospun core-shell nanofibers and spread up the release of active proteins from their core. Electrospinning can be used for the preparation of the core-shell nanofibers, where active ingredients are encapsulated in the core and their release rate is regulated by the shell. However, such fibers are usually prepared by coaxial electrospinning that is an extremely low-throughput technique. An alternative is emulsion electrospinning that could be upscaled using needleless blades. In this work, we investigate the possibility of using emulsion electrospinning for encapsulation and sustained release of the growth factors for the development of the organotypic skin models. The core-shell nanofibers were prepared using the optimized formulation and the release rate of proteins from the fibers was investigated for 2 weeks – typical cell culture conditions.

Keywords: electrospinning, polycaprolactone (PCL), polyethylene oxide (PEO), polyvinylpyrrolidone (PVP)

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13 ADA Tool for Satellite InSAR-Based Ground Displacement Analysis: The Granada Region

Authors: M. Cuevas-González, O. Monserrat, A. Barra, C. Reyes-Carmona, R.M. Mateos, J. P. Galve, R. Sarro, M. Cantalejo, E. Peña, M. Martínez-Corbella, J. A. Luque, J. M. Azañón, A. Millares, M. Béjar, J. A. Navarro, L. Solari

Abstract:

Geohazard prone areas require continuous monitoring to detect risks, understand the phenomena occurring in those regions and prevent disasters. Satellite interferometry (InSAR) has come to be a trustworthy technique for ground movement detection and monitoring in the last few years. InSAR based techniques allow to process large areas providing high number of displacement measurements at low cost. However, the results provided by such techniques are usually not easy to interpret by non-experienced users hampering its use for decision makers. This work presents a set of tools developed in the framework of different projects (Momit, Safety, U-Geohaz, Riskcoast) and an example of their use in the Granada Coastal area (Spain) is shown. The ADA (Active Displacement Areas) tool have been developed with the aim of easing the management, use and interpretation of InSAR based results. It provides a semi-automatic extraction of the most significant ADAs through the application ADAFinder tool. This tool aims to support the exploitation of the European Ground Motion Service (EU-GMS), which will provide consistent, regular and reliable information regarding natural and anthropogenic ground motion phenomena all over Europe.

Keywords: ground displacements, InSAR, natural hazards, satellite imagery

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12 Agile Methodology for Modeling and Design of Data Warehouses -AM4DW-

Authors: Nieto Bernal Wilson, Carmona Suarez Edgar

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The organizations have structured and unstructured information in different formats, sources, and systems. Part of these come from ERP under OLTP processing that support the information system, however these organizations in OLAP processing level, presented some deficiencies, part of this problematic lies in that does not exist interesting into extract knowledge from their data sources, as also the absence of operational capabilities to tackle with these kind of projects.  Data Warehouse and its applications are considered as non-proprietary tools, which are of great interest to business intelligence, since they are repositories basis for creating models or patterns (behavior of customers, suppliers, products, social networks and genomics) and facilitate corporate decision making and research. The following paper present a structured methodology, simple, inspired from the agile development models as Scrum, XP and AUP. Also the models object relational, spatial data models, and the base line of data modeling under UML and Big data, from this way sought to deliver an agile methodology for the developing of data warehouses, simple and of easy application. The methodology naturally take into account the application of process for the respectively information analysis, visualization and data mining, particularly for patterns generation and derived models from the objects facts structured.

Keywords: data warehouse, model data, big data, object fact, object relational fact, process developed data warehouse

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11 Bioremediation Potential in Recalcitrant Areas of PCE in Alluvial Fan Deposits

Authors: J. Herrero, D. Puigserver, I. Nijenhuis, K. Kuntze, J. M. Carmona

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In the transition zone between aquifers and basal aquitards, the perchloroethene (PCE)-pools are more recalcitrant than those elsewhere in the aquifer. Although biodegradation of chloroethenes occur in this zone, it is a slow process and a remediation strategy is needed. The aim of this study is to demonstrate that combined strategy of biostimulation and in situ chemical reduction (ISCR) is more efficient than the two separated strategies. Four different microcosm experiments with sediment and groundwater of a selected field site where an aged pool exists at the bottom of a transition zone were designed under i) natural conditions, ii) biostimulation with lactic acid, iii) ISCR with zero-value iron (ZVI) and under iv) a combined strategy with lactic acid and ZVI. Biotic and abiotic dehalogenation, terminal electron acceptor processes and evolution of microbial communities were determined for each experiment. The main results were: i) reductive dehalogenation of PCE-pools occurs under sulfate-reducing conditions; ii) biostimulation with lactic acid supports more pronounced reductive dehalogenation of PCE and trichloroethene (TCE), but results in an accumulation of 1,2-cis-dichloroethene (cDCE); iii) ISCR with ZVI produces a sustained dehalogenation of PCE and its metabolites iv) combined strategy of biostimulation and ISCR results in a fast dehalogenation of PCE and TCE and a sustained dehalogenation of cisDCE. These findings suggest that biostimulation and ISCR with ZVI are the most suitable strategies for a complete reductive dehalogenation of PCE-pools in the transition zone and further to enable the dissolution of dense non-aqueous phase liquids.

Keywords: aged PCE-pool, anaerobic microcosm experiment, biostimulation, in situ chemical reduction, natural attenuation

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10 Desirable Fatty Acids in Meat of Cattle Fed Different Levels of Lipid-Based Diets

Authors: Tiago N. P. Valente, Erico S. Lima, Roberto O. Roça

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Introduction: Research has stimulated animal production studies on solutions to decrease the level of saturated fatty acids and increase unsaturated in foods of animal origin. The objective of this study was to determine the effect of the dietary inclusion of lipid-based diets on the fatty acid profiles from finishing cattle. Materials and Methods: The study was carried out in the Chapéu de Couro Farm in Aguaí/SP, Brazil. A group of 39 uncastrated Nellore cattle. Mean age of the animals was 36 months, and initial mean live weight was 494.1 ± 10.1. Animals were randomly assigned to one of three treatments, based on dry matter: feed with control diet 2.50% cottonseed, feed with 11.50% cottonseed, and feed with 3.13% cottonseed added of 1.77% protected lipid. Forage:concentrate ratio was 50:50 on a dry matter basis. Sugar cane chopped was used as forage. After 63 days mean final live weight was 577.01 kg ± 11.34. After slaughter, carcasses were identified and divided into two halves that were kept in a cold chamber for 24 hours at 2°C. Then, part of the M. longissimus thoracis of each animal was removed between the 12th and 13th rib of the left half carcass. The samples steaks were 2.5 cm thick and were identified and stored frozen in a freezer at -18°C. The analysis of methyl esters of fatty acids was carried out in a gas chromatograph. Desirable fatty acids (FADes) were determined by the sum of unsaturated fatty acids and stearic acid (C18:0). Results and Discussion: No differences (P>0.05) between the diets for the proportion of FADes in the meat of the animals in this study, according to the lipid sources used. The inclusion of protected fat or cottonseed in the diet did not change the proportion of FADes in the meat. The proportion mean of FADes in meat in the present study were: as pentadecanoic acid (C15:1 = 0.29%), palmitoleic acid (C16:1 = 4.26%), heptadecanoic acid (C17:1 = 0.07%), oleic acid (C18:1n9c = 37.32%), γ-linolenic acid (0.94%) and α-linolenic acid (1.04%), elaidic acid (C18:1n9t = 0.50%), eicosatrienoic acid (C20:3n3 = 0.03%), eicosapentaenoic acid (C20:5n3 = 0.04%), erucic acid (C22:1n9 = 0.89%), docosadienoic acid (C22:2 = 0.04%) and stearic acid (C18:0 = 21.53%). Conclusions: The add the cottonseed or protected lipid in diet is not affected fatty acids profiles the desirable fatty acids in meat. Acknowledgements: IFGoiano, FAPEG and CNPq (Brazil).

Keywords: beef quality, cottonseed, protected fat, unsaturated fatty acids

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9 A Mixed Methods Research Design for the Development of the Xenia Higher Education Institutions' Inclusiveness Index

Authors: Achilles Kameas, Eleni Georgakakou, Anna Lisa Amodeo, Aideen Quilty, Aisling Malone, Roberta Albertazzi, Moises Carmona, Concetta Esposito, Ruben David Fernandez Carrasco, Carmela Ferrara, Francesco Garzillo, Mojca Pusnik, Maria Cristina Scarano

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While researchers, especially in academia, study and research the phenomena of inclusion of sexual minority and gender marginalized groups, seldom the European Higher Education Institutions (HEI) act on lowering the cultural and educational barriers to their proactive inclusion. The challenge in European HEIs is that gender, and sexual orientation discrimination remains an issue not adequately addressed. Following a mixed methods research design of quantitative and qualitative research techniques and tools, which is applied in five (5) European countries (Italy, Greece, Ireland, Slovenia, and Spain) and that combines desk research, evaluation, and weighting processes for a Matrix-based on Objective indicators and Survey for students and staff of the HEI to gauge the perception of inclusiveness in the HEI context, XENIA HEI Inclusiveness Index is an instrument that will allow universities to gauge and assess their inclusiveness in the domain of discrimination and exclusion based on gender identity and sexual orientation. The index will allow capturing the depth and reach of policies, programmes, and initiatives of HEIs in tackling the phenomena and dynamics of exclusion of LGBT+ (lesbian, gay, bisexual, trans, and other marginalized groups on the basis of gender and sexual identity) and cisgender women exposed to the risk of discrimination.

Keywords: gender identity, higher education, LGBT+ rights, XENIA inclusiveness index

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8 Variation in pH Values and Tenderness of Meat of Cattle Fed Different Levels of Lipids

Authors: Erico Da Silva Lima, Tiago Neves Pereira Valente, Roberto De Oliveira Roça

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Introduction: Over the last few years the market has increased its demand for high quality meat. Based on this premise some producers have continuously improved their efficiency in breeding beef cattle with the purpose to support this demand. It is well recognized that final quality of beef is intimately linked to animal’s diet. The key objective of this study is to evaluate the influence of feeding animals with cottonseed and its lipids and the final results in terms of pH and shear forces of the meat. Materials and Methods: The study was carried out in the Chapéu de Couro Farm in Aguaí/SP, Brazil. A group of 39 uncastrated Nellore cattle. Mean age of the animals was 36 months and initial mean live weight was 494.1 ± 10.1. Animals were randomly assigned to one of three treatments, based on dry matter: feed with control diet 2.50% cottonseed, feed with 11.50% cottonseed, and feed with 3.13% cottonseed added of 1.77% protected lipid. Forage:concentrate ratio was 50:50 on a dry matter basis. Sugar cane chopped was used as forage. After slaughter, carcasses were identified and divided into two halves that were kept in a cold chamber for 24 h at 2°C. Using pH meter was determined post-mortem pH in Longissimus thoracis muscle between the 12th and 13th rib of the left half carcass. After, part of each animal was removed, and divided in three samples (steaks). Steaks were 2.5 cm thick and were identified and stored individually in plastic bags under vacuum. Samples were frozen in a freezer at -18°C. The same samples cooked were refrigerated by 12 h the 4°C, and then cut into cylinders 1.10 Øcm with the support of a drill press avoiding fats and nerves. Shear force was calculated in these samples cut into cylinders through the Brookfield texture CT3 Texture Analyzer 25 k equipped with a set of blade Warner-Bratzler. Results and Discussion: No differences (P > 0.05) in pH 24 h after slaughter were observed in the meat of Nellore cattle fed different sources of fat, and mean value for this variable was 5.59. However, for the shear force differences (P < 0.05) were founded. For diet with 2,50% cottonseed the lowest value found 5.10 (kg) while for the treatment with 11.50% cottonseed the great value found was 6.30 (kg). High shear force values mean greater texture of meat that indicates less tenderness. The texture of the meat can be influenced by age, weight to the slaughter of animals. For cattle breed Nellore Bos taurus indicus more high value of shear force. Conclusions: The add the cottonseed or protected lipid in diet is not affected pH values in meat. The whole cottonseed does not contribute to the improvement of tenderness of the meat. Acknowledgments: IFGoiano, FAPEG and CNPq (Brazil).

Keywords: beef quality, cottonseed, protected fat, shear force

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7 Indigenous Understandings of Climate Vulnerability in Chile: A Qualitative Approach

Authors: Rosario Carmona

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This article aims to discuss the importance of indigenous people participation in climate change mitigation and adaptation. Specifically, it analyses different understandings of climate vulnerability among diverse actors involved in climate change policies in Chile: indigenous people, state officials, and academics. These data were collected through participant observation and interviews conducted during October 2017 and January 2019 in Chile. Following Karen O’Brien, there are two types of vulnerability, outcome vulnerability and contextual vulnerability. How vulnerability to climate change is understood determines the approach, which actors are involved and which knowledge is considered to address it. Because climate change is a very complex phenomenon, it is necessary to transform the institutions and their responses. To do so, it is fundamental to consider these two perspectives and different types of knowledge, particularly those of the most vulnerable, such as indigenous people. For centuries and thanks to a long coexistence with the environment, indigenous societies have elaborated coping strategies, and some of them are already adapting to climate change. Indigenous people from Chile are not an exception. But, indigenous people tend to be excluded from decision-making processes. And indigenous knowledge is frequently seen as subjective and arbitrary in relation to science. Nevertheless, last years indigenous knowledge has gained particular relevance in the academic world, and indigenous actors are getting prominence in international negotiations. There are some mechanisms that promote their participation (e.g., Cancun safeguards, World Bank operational policies, REDD+), which are not absent from difficulties. And since 2016 parties are working on a Local Communities and Indigenous Peoples Platform. This paper also explores the incidence of this process in Chile. Although there is progress in the participation of indigenous people, this participation responds to the operational policies of the funding agencies and not to a real commitment of the state with this sector. The State of Chile omits a review of the structure that promotes inequality and the exclusion of indigenous people. In this way, climate change policies could be configured as a new mechanism of coloniality that validates a single type of knowledge and leads to new territorial control strategies, which increases vulnerability.

Keywords: indigenous knowledge, climate change, vulnerability, Chile

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6 Lactate Biostimulation for Remediation of Aquifers Affected by Recalcitrant Sources of Chloromethanes

Authors: Diana Puigserver Cuerda, Jofre Herrero Ferran, José M. Carmona Perez

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In the transition zone between aquifers and basal aquitards, DNAPL-pools of chlorinated solvents are more recalcitrant than at other depths in the aquifer. Although degradation of carbon tetrachloride (CT) and chloroform (CF) occurs in this zone, this is a slow process, which is why an adequate remediation strategy is necessary. The working hypothesis of this study is that the biostimulation of the transition zone of an aquifer contaminated by CT and CF can be an effective remediation strategy. This hypothesis has been tested in a site on an unconfined aquifer in which the major contaminants were CT and CF of industrial origin and where the hydrochemical background was rich in other compounds that can hinder natural attenuation of chloromethanes. Field studies and five laboratory microcosm experiments were carried out at the level of groundwater and sediments to identify: i) the degradation processes of CT and CF; ii) the structure of microbial communities; and iii) the microorganisms implicated on this degradation. For this, concentration of contaminants and co-contaminants (nitrate and sulfate), Compound Specific Isotope Analysis, molecular techniques (Denaturing Gradient Gel Electrophoresis) and clone library analysis were used. The main results were: i) degradation processes of CT and CF occurred in groundwater and in the lesser conductive sediments; ii) sulfate-reducing conditions in the transition zone were high and similar to those in the source of contamination; iii) two microorganisms (Azospira suillum and a bacterium of the Clostridiales order) were identified in the transition zone at the field and lab experiments that were compatible with the role of carrying out the reductive dechlorination of CT, CF and their degradation products (dichloromethane and chloromethane); iv) these two microorganisms were present at the high starting concentrations of the microcosm experiments (similar to those in the source of DNAPL) and continued being present until the last day of the lactate biostimulation; and v) the lactate biostimulation gave rise to the fastest and highest degradation rates and promoted the elimination of other electron acceptors (e.g. nitrate and sulfate). All these results are evidence that lactate biostimulation can be effective in remediating the source and plume, especially in the transition zone, and highlight the environmental relevance of the treatment of contaminated transition zones in industrial contexts similar to that studied.

Keywords: Azospira suillum, lactate biostimulation of carbon tetrachloride and chloroform, reductive dechlorination, transition zone between aquifer and aquitard

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5 The Effect of Configuration Space and Visual Perception in Public Space Usage at Villa Bukit Tidar Housing in Malang City

Authors: Aisyiyah Fauziah Rahmah

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Generally, an urban city has a rapid growth, it has frequent a variety of problems, especially of convenience in public space usage. The density of population in urban areas and the high activity is also indicated as a cause of urban resident lifestyle for the worse in social relationships and allow for the stress. Streets and green space (parks) are the only public space in a residential area which is used as a place to build social activity, to meet and interact with the other housing dweller. The high level of activity and social interaction that occurs will affect the spatial arrangement. It can be effected the space structures in housing more complex. Ease in access to public space is the reason many dweller prefer doing social activities there. Hillier in Carmona et al (2003) explains that the pattern and intensity of movement of individuals is influenced by the configuration of space, even the space structure can be regarded as the single most influential determinant of movements in the space. Whyte in Zhang and Lawson (2009) also suggest some factors such as seats, trees, water and legibility of space encourage people to stay in public outdoor space. Furthermore this activities can attract more activities. Villa Bukit Tidar is a housing in Lowokwaru District which highest number of people in Malang City, so social activity is also high there. It has natural and recreational concept and provided with view of Malang City from heights. This potential is able to attract the people who live there to stay in public outdoor space and doing activities there. From this study we can find whether the ease of access to public space and visual satisfaction of Villa Bukit Tidar housing affect the usage of public space. This study was carried out by observing the streets pattern and plot pattern to know the configuration space of Villa Bukit Tidar housing through values of connectivity and integrity by resulting from space sintax analysis. Distributing questionnaires also carried out to determine the level of satisfaction and importance perception of visual condition in the public space in Villa Bukit Tidar housing through Important Performance Analysis (IPA). Results of this research indicated that the public spaces in Villa Bukit Tidar housing who has high connectivity and integrity is considered to be visually satisfied and it has a higher public space usage than has low connectivity and integrity are considered to be visually dissatisfied.

Keywords: configuration space, visual perception, social activities, public space usage

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4 Connectivity: Connecting ActivityRethinking Streets as Public Space under the Six Dimensions of Urban Space Design in the Context of Bangladesh

Authors: Manal Anis, Bin Bakhti Sayeed

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With the encroachment of automobile upon our communities for decades and the concomitant urban sprawl resulting in a loss of public place, it was only a matter of time before people, realizing the role of streets in stimulating urban prosperity, would start reclaiming them to rebuild their communities. In order for this restoration of communities to take effect it is imperative that streets be freed from the dominance of motor vehicles. A holistic approach to pedestrian-friendly street environment can help build communities that embody the cities in which they are found. While the developed countries are finding more and more innovative ways to integrate walkable streets to foster communal living, the developing countries still have a long way to go. Since Dhaka is still struggling to balance the growing needs of accommodating automobiles for increased population with the loss of urban community life that comes with it, it is high time that alternate approaches are looked into. This study aims to understand streets as a living corridor through which one discovers and identifies with the city. The research area is chosen to be Manik Mia Avenue, overlooking the South Plaza of the National Parliament Building in Dhaka city. Being the site of supreme power, it is precisely this symbolic importance that the National Parliament Building has in the psyche of Bangladeshis, which has given Manik Mia Avenue a significant place in the country’s history. Above all, being an avenue it is essentially a neutral territory, universally accessible, inclusive and pluralist. The needs of the Avenue’s frequent users are analyzed with the help of a multi-method approach to survey consisting of an empirical study, a questionnaire survey and interview with relevant users. The research then tries to understand the concept of walkability by exploring the different ways in which the built environment influences walking. For this analysis, the six dimensions of Matthew Carmona are taken as a guideline for a holistic approach toward the different interacting facets of an urban public space. Based on the studies, a set of criteria is proposed to evaluate, plan and design streets that are more contextual in nature. The study concludes with how the existing street patterns of Dhaka city can be rethought and redesigned to cater to peoples’ need for a public place. The proposal is meant to be an inspiration for further studies in this respect in the context of Bangladesh.

Keywords: public space, six dimensions, street, urban, walkability

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3 Poly(Methyl Methacrylate) Degradation Products and Its in vitro Cytotoxicity Evaluation in NIH3T3 Cells

Authors: Lesly Y Carmona-Sarabia, Luisa Barraza-Vergara, Vilmalí López-Mejías, Wandaliz Torres-García, Maribella Domenech-Garcia, Madeline Torres-Lugo

Abstract:

Biosensors are used in many applications providing real-time monitoring to treat long-term conditions. Thus, understanding the physicochemical properties and biological side effects on the skin of polymers (e. g., poly(methyl methacrylate), PMMA) employed in the fabrication of wearable biosensors is crucial for the selection of manufacturing materials within this field. The PMMA (hydrophobic and thermoplastic polymer) is commonly employed as a coating material or substrate in the fabrication of wearable devices. The cytotoxicityof PMMA (including residual monomers or degradation products) on the skin, in terms of cells and tissue, is required to prevent possible adverse effects (cell death, skin reactions, sensitization) on human health. Within this work, accelerated aging of PMMA (Mw ~ 15000) through thermal and photochemical degradation was under-taken. The accelerated aging of PMMA was carried out by thermal (200°C, 1h) and photochemical degradation (UV-Vis, 8-15d) adapted employing ISO protocols (ISO-10993-12, ISO-4892-1:2016, ISO-877-1:2009, ISO-188: 2011). In addition, in vitro cytotoxicity evaluation of PMMA degradation products was performed using NIH3T3 fibroblast cells to assess the response of skin tissues (in terms of cell viability) exposed with polymers utilized to manufacture wearable biosensors, such as PMMA. The PMMA (Mw ~ 15000) before and after accelerated aging experiments was characterized by thermal gravimetric analysis (TGA), differential scanning calorimetric (DSC), powder X-ray diffractogram (PXRD), and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) to determine and verify the successful degradation of this polymer under the specific conditions previously mention. The degradation products were characterized through nuclear magnetic resonance (NMR) to identify possible byproducts generated after the accelerated aging. Results demonstrated a percentage (%) weight loss between 1.5-2.2% (TGA thermographs) for PMMA after accelerated aging. The EDS elemental analysis reveals a 1.32 wt.% loss of carbon for PMMA after thermal degradation. These results might be associated with the amount (%) of PMMA degrade after the accelerated aging experiments. Furthermore, from the thermal degradation products was detected the presence of the monomer and methyl formate (low concentrations) and a low molecular weight radical (·COOCH3) in higher concentrations by NMR. In the photodegradation products, methyl formate was detected in higher concentrations. These results agree with the proposed thermal or photochemical degradation mechanisms found in the literature.1,2 Finally, significant cytotoxicity on the NIH3T3 cells was obtained for the thermal and photochemical degradation products. A decrease in cell viability by > 90% (stock solutions) was observed. It is proposed that the presence of byproducts (e.g. methyl formate or radicals such as ·COOCH₃) from the PMMA degradation might be responsible for the cytotoxicity observed in the NIH3T3 fibroblast cells. Additionally, experiments using skin models will be employed to compare with the NIH3T3 fibroblast cells model.

Keywords: biosensors, polymer, skin irritation, degradation products, cell viability

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2 Comparative Analysis on the Evolution of Chlorinated Solvents Pollution in Granular Aquifers and Transition Zones to Aquitards

Authors: José M. Carmona, Diana Puigserver, Jofre Herrero

Abstract:

Chlorinated solvents belong to the group of nonaqueous phase liquids (DNAPL) and have been involved in many contamination episodes. They are carcinogenic and recalcitrant pollutants that may be found in granular aquifers as: i) pools accumulated on low hydraulic conductivity layers; ii) immobile residual phase retained at the pore-scale by capillary forces; iii) dissolved phase in groundwater; iv) sorbed by particulate organic matter; and v) stored into the matrix of low hydraulic conductivity layers where they penetrated by molecular diffusion. The transition zone between granular aquifers and basal aquitards constitute the lowermost part of the aquifer and presents numerous fine-grained interbedded layers that give rise to significant textural contrasts. These layers condition the transport and fate of contaminants and lead to differences from the rest of the aquifer, given that: i) hydraulic conductivity of these layers is lower; ii) DNAPL tends to accumulate on them; iii) groundwater flow is slower in the transition zone and consequently pool dissolution is much slower; iv) sorbed concentrations are higher in the fine-grained layers because of their higher content in organic matter; v) a significant mass of pollutant penetrates into the matrix of these layers; and vi) this contaminant mass back-diffuses after remediation and the aquifer becomes contaminated again. Thus, contamination sources of chlorinated solvents are extremely more recalcitrant in transition zones, which has far-reaching implications for the environment. The aim of this study is to analyze the spatial and temporal differences in the evolution of biogeochemical processes in the transition zone and in the rest of the aquifer. For this, an unconfined aquifer with a transition zone in the lower part was selected at Vilafant (NE Spain). This aquifer was contaminated by perchloroethylene (PCE) in the 80’s. Distribution of PCE and other chloroethenes in groundwater and porewater was analyzed in: a) conventional piezometers along the plume and in two multilevel wells at the source of contamination; and b) porewater of fine grained materials from cores recovered when drilled the two multilevel wells. Currently, the highest concentrations continue to be recorded in the source area in the transition zone. By contrast, the lowest concentrations in this area correspond to the central part of the aquifer, where flow velocities are higher and a greater washing of the residual phase initially retained has occurred. The major findings of the study were: i) PCE metabolites were detected in the transition zone, where conditions were more reducing than in the rest of the aquifer; ii) however, reductive dechlorination was partial since only the formation of cis-dicholoroethylene (DCE) was reached; iii) In the central part of the aquifer, where conditions were predominantly oxidizing, the presence of nitrate significantly hindered the reductive declination of PCE. The remediation strategies to be implemented should be directed to enhance dissolution of the source, especially in the transition zone, where it is more recalcitrant. For example, by combining chemical and bioremediation methods, already tested at the laboratory scale with groundwater and sediments of this site.

Keywords: chlorinated solvents, chloroethenes, DNAPL, partial reductive dechlorination, PCE, transition zone to basal aquitard

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1 Anti-Infective Potential of Selected Philippine Medicinal Plant Extracts against Multidrug-Resistant Bacteria

Authors: Demetrio L. Valle Jr., Juliana Janet M. Puzon, Windell L. Rivera

Abstract:

From the various medicinal plants available in the Philippines, crude ethanol extracts of twelve (12) Philippine medicinal plants, namely: Senna alata L. Roxb. (akapulko), Psidium guajava L. (bayabas), Piper betle L. (ikmo), Vitex negundo L. (lagundi), Mitrephora lanotan (Blanco) Merr. (Lanotan), Zingiber officinale Roscoe (luya), Curcuma longa L. (Luyang dilaw), Tinospora rumphii Boerl (Makabuhay), Moringga oleifera Lam. (malunggay), Phyllanthus niruri L. (sampa-sampalukan), Centella asiatica (L.) Urban (takip kuhol), and Carmona retusa (Vahl) Masam (tsaang gubat) were studied. In vitro methods of evaluation against selected Gram-positive and Gram-negative multidrug-resistant (MDR), bacteria were performed on the plant extracts. Although five of the plants showed varying antagonistic activities against the test organisms, only Piper betle L. exhibited significant activities against both Gram-negative and Gram-positive multidrug-resistant bacteria, exhibiting wide zones of growth inhibition in the disk diffusion assay, and with the lowest concentrations of the extract required to inhibit the growth of the bacteria, as supported by the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. Further antibacterial studies of the Piper betle L. leaf, obtained by three extraction methods (ethanol, methanol, supercritical CO2), revealed similar inhibitory activities against a multitude of Gram-positive and Gram-negative MDR bacteria. Thin layer chromatography (TLC) assay of the leaf extract revealed a maximum of eight compounds with Rf values of 0.92, 0.86, 0.76, 0.53, 0.40, 0.25, 0.13, and 0.013, best visualized when inspected under UV-366 nm. TLC- agar overlay bioautography of the isolated compounds showed the compounds with Rf values of 0.86 and 0.13 having inhibitory activities against Gram-positive MDR bacteria (MRSA and VRE). The compound with an Rf value of 0.86 also possesses inhibitory activity against Gram-negative MDR bacteria (CRE Klebsiella pneumoniae and MBL Acinetobacter baumannii). Gas Chromatography-Mass Spectrometry (GC-MS) was able to identify six volatile compounds, four of which are new compounds that have not been mentioned in the medical literature. The chemical compounds isolated include 4-(2-propenyl)phenol and eugenol; and the new four compounds were ethyl diazoacetate, tris(trifluoromethyl)phosphine, heptafluorobutyrate, and 3-fluoro-2-propynenitrite. Phytochemical screening and investigation of its antioxidant, cytotoxic, possible hemolytic activities, and mechanisms of antibacterial activity were also done. The results showed that the local variant of Piper betle leaf extract possesses significant antioxidant, anti-cancer and antimicrobial properties, attributed to the presence of bioactive compounds, particularly of flavonoids (condensed tannin, leucoanthocyanin, gamma benzopyrone), anthraquinones, steroids/triterpenes and 2-deoxysugars. Piper betle L. is also traditionally known to enhance wound healing, which could be primarily due to its antioxidant, anti-inflammatory and antimicrobial activities. In vivo studies on mice using 2.5% and 5% of the ethanol leaf extract cream formulations in the excised wound models significantly increased the process of wound healing in the mice subjects, the results and values of which are at par with the current antibacterial cream (Mupirocin). From the results of the series of studies, we have definitely proven the value of Piper betle L. as a source of bioactive compounds that could be developed into therapeutic agents against MDR bacteria.

Keywords: Philippine herbal medicine, multidrug-resistant bacteria, Piper betle, TLC-bioautography

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