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The effectiveness was evaluated for an established wood preservative, zinc borate, prepared in an agitating bead mill to extensively reduce its particle size. The generated micro- or nano-particles of zinc borate were characterized by X-ray powder diffraction, and the particle size distribution was determined to evaluate the effect of milling. Then the fungicidal effectiveness of the zinc borate of both milled and unmilled samples were assayed against brown- and white-rot fungi, on culture medium and on conifer and hardwood as substrates. Treated wood samples were subjected to leaching tests. Scanning electron microscopic images of wood samples were examined to analyze the distribution of zinc borate within the wood. The micronized zinc product kept its crystal structure intact, and it increased the proportion of particles with diameters below 100 nm by 25% when compared to the unmilled product. Malt extract-agar medium supplemented with 2.5% of w/w milled and unmilled zinc borate inhibited fungal growth tested. Both milled and unmilled zinc borate protected the wood when not subjected to leaching. The milled sample of zinc borate improved resistance to leaching, which would allow its application in environments of high moisture content; however, it did not improve the fungicidal action against decay fungi.

Wood is a common construction material used in most environments. However, its sensibility to abiotic agents, in particular those that affect the dimensional stability, limits the durability of the material and decreases its properties. In this work, the efficiency of a paraffin-emulsion-based product as a water repellent, combined with the selection of Eucalyptus grandis clones with a low cracking index, was tested for its use in utility poles in order to improve the woods dimensional stability. Four selected Eucalyptus grandis clones were treated with the product mixed with Chromated Copper Arsenate - the most commonly used wood protector - in a single stage by the Bethell method at two retention levels. The dimensional stability of the treated samples was studied through the determination of anti-shrink efficiency. Test samples were also exposed to accelerated weathering processes for 200 h, and later analyzed by SEM microscopy. Results showed a significant improvement in the dimensional stability of treated wood when compared to samples without the water repellent, with variable efficacy depending on the clone used. Despite the weathering process slightly affected the appearance of the wood surface, the product is suitable for exterior use.

The biological decomposition of lignocellulosic materials caused by basidiomycetes plays an essential role in the carbon cycle. Brown rot fungi represent important agents in the biodegradation of wood products and standing coniferous trees in natural ecosystems. The initial moisture content of the wood is an important factor in the degradation process. In this work, the effects of initial moisture content of Eucalyptus grandis sapwood on decay by two brown rot fungi Gloeophyllum trabeum and Laetiporus sulphureus were studied over a 10-month period. The fungal activity was evaluated, through wood weight loss, moisture content, anatomical changes (scan electronic and fluorescence microscopy) and Fourier-transform infrared spectroscopy. Weight loss increased through the 10-month test for both fungi, Laetiporus sulphureus producing higher mass losses. Colonization of the wood by both fungi started below the fiber saturation range. It was observed that the initial moisture content of the wood influenced the rate of deterioration: the wet samples showed higher weight loss compared to the dry samples. Changes in the chemical composition and structure of cell walls were detected. The initial moisture content of the substrate affected the development of the fungi, slowing their growth.

This paper empirically examines the behavioral precautionary saving hypothesis by Koszegi and Rabin (2009) stating that uncertainty about future income triggers saving because of loss aversion. We extend their theoretical analysis to also consider the internal margin, i.e., the strength, of loss aversion, and empirically study the relation between income risk, experimentally elicited loss aversion and precautionary savings. We do so using a sample of 640 individuals from the low-income population of Bogota, characterized by limited financial education and subject to substantial income risk. In line with the theoretical predictions, we find that an increase in income risk is associated with higher savings for loss-averse individuals, and that this increase in savings grows with the degree of loss aversion. Thus, as suggested by Koszegi and Rabin (2009), but contrarily to common assumptions, our findings establish that loss aversion is not necessarily an obstacle to saving, and thus identify new approaches of increasing saving among individuals with low financial education.

Zinc borate has long been used as a protector for wood products due to its fungicide, insecticide and flame retardant properties. In this initial study, its capacity as a flame retardant when applied to Eucalyptus grandis wood is evaluated; micronized zinc borate, synthesized from zinc oxide and boric acid in our laboratory was used. The methodology used in the study is the use of the Vandersall tunnel, which allowed analyzing parameters such as the flame spread, the carbonization index, the carbonization area and the wood weight loss. The results show a remarkable improvement in these parameters after the application of micronized zinc borate. For the longest fire exposure time, the percentage decrease of each evaluated parameter is, for tangential and radial plane respectively: 31.27-43.00% for flame spread, 36.66-40.86% for carbonization area, 33.01-52.49% for carbonization index and 19.86-57.80% for mass loss.

Affirmative action to promote women's employment is a intensely debated policy. Do affirmative action policies attract women and does it come at a cost of deterring high qualified men? In three field experiments in Colombia we compare characteristics of job-seekers who are told of the affirmative action selection criterion before they apply with those who are only told after applying. We find that the gains in attracting female applicants far outweigh the losses in male applicants. Affirmative action is more effective in areas with larger female discrimination and deters male job-seekers from areas with low discrimination.

This paper investigates the trade-off between conservation and equity considerations in the use of payments for environmental services (PES) that implicitly incorporate different distributive justice principles. Using a public good experiment with heterogeneous participants, we compare the effects on additional area conserved and distribution of earnings of two PES schemes: an equal payment and a payment based on Rawls distributional principle, which we refer to as maxi-min payment scheme. The main findings of the framed field experiment conducted in Jambi province (Indonesia) indicate that the introduction of a maxi-min PES scheme can function as a multi-purpose instrument. It realigns the income distribution in favor of low-endowed participants and does not necessarily need to be compromised by lower environmental additionality at the group level.

The intense debate on the effectiveness of the war on drugs contrasts with the scarce quantitative evidence on its impacts on drug cultivation decisions by individual producers. Using panel data fr...

We compared resistance to decay, mold fungi, termites and insect larvae of particleboards incorporated with the raw boron minerals ulexite and colemanite to that of particleboards impregnated with the commercial boron preservative zinc borate, or boric acid plus a borax mixture. We also quantified water absorption, thickness swell and boron release of particleboards. Ulexite had the best decay resistance, and colemanite had the best termite resistance. However, ulexite and colemanite were not as effective as zinc borate or the boric acid/borax mixture in preventing mold growth. In general, the boric acid/borax mixture combination was more effective against Anobium larvae than the other treatments. Less boron was released by specimens containing zinc borate and colemanite than by those containing ulexite or the boric acid/borax mixture. In general, water absorption and thickness swell were similar among the different treatments, but both were slightly higher in the ulexite-incorporated specimens. Further mechanical tests will be needed to evaluate the particleboard properties and thereby the compatibility of these boron minerals with various manufacturing processes.

According to advocates, eco-certification is a win–win solution to the problem of environmental degradation caused by developing country agriculture, improving both the environmental and the economic performance of farmers. However, these notional benefits can be undercut by the tendency of relatively wealthy farmers already meeting eco-certification standards to disproportionately participate. Using original farm-level survey data along with matching and matched difference-in-differences models, we analyze the producer-level effects of organic coffee certification in southeastern Colombia. We find that certification is associated with changes in farm practices linked to improved environmental outcomes. It significantly reduces sewage disposal in the fields and increases the adoption of organic fertilizer. However, we are not able to discern economic benefits.

A través de un ensayo de campo implementado de acuerdo a la norma EN 252, se evaluó la efectividad de tratamientos en etapas, tendientes a disminuir la lixiviación de una solución rica en Zn y Mn obtenida a partir de un proceso de reciclado aplicada en la madera por el método Bethell. La segunda etapa antilixiviante agregó bórax por pincelado o por el método Bethell. Se utilizó madera de Pinus taeda. Este trabajo presenta el análisis de la evolución del proceso de deterioro a lo largo de 5 años de ensayo de campo y su evaluación. Se utilizó el índice climático de Scheffer como método de evaluación del riesgo microbiológico en el sitio del ensayo y se realizó un análisis microscópico de la madera, para verificar el tipo de deterioro presente. Los tratamientos al 3% y al 6% en Zn con agregado de bórax por el método Bethell fueron los de mejor desempeño entre los evaluados a pesar de no haber superado el desempeño del preservante de referencia. Se observó la presencia de los tres tipos de pudrición, blanca, marrón y blanda tanto en controles sin tratamiento como en maderas tratadas, en un sitio con condiciones intermedias para el deterioro.

The aim of this research was to quantify and identify the types of lignin and characterize its functionalization based on apparent physical resistance in each seed coat layers of Araucaria angustifolia. Each seed layer (exotesta, mesotesta and endotesta) was milled, homogenized and pre-extracted with solvents: cyclohexane, ethyl acetate and methanol for quantification of lignin. Pre-treatment with NaOH 1% was also performed in each layer of the seed for lignin quantification and for infrared spectroscopy. The lignin content obtained in the testa was 32.43 % for the three layers. After alkaline treatment, the lignin content was 31.52 % in exotesta, 16.88 % in mesotesta and 15.48 % in endotesta. Dioxane lignin was isolated from the seed coat and reduced with NaHB4. Infrared spectra (FTIR) were obtained from the dioxane lignin, reduced dioxane lignin and alkaline-treated Klason lignin of each layer. Microscopic analyses of the in natura exotesta and mesotesta layers from the seed coat were performed through histochemical test (Wiesner) and fluorescence microscopy. Infrared analyses made possible observation of aldehyde terminations in dioxane lignin and propose the structural profile of Klason lignin in different layers. Fluorescence microscopic analyses allowed identification of highly lignified macrosclereids in exotesta. El objetivo de esta investigación fue identificar y cuantificar los tipos de lignina, y caracterizar su función según la resistencia física aparente de cada capa de la testa de la semilla de Araucaria angustifolia. Cada capa de la semilla (exotesta, mesotesta e endotesta) se molió, homogeneizó y sometió a un ciclo de pre-extracción con solventes (ciclohexano, acetato de etilo y metanol) para preparar el material para cuantificar la lignina. También se realizó en cada capa de la semilla un pre-tratamiento con NaOH 1 % para cuantificar la lignina y para aplicar espectroscopía infrarroja. El contenido de lignina en la testa fue 32,43 % para las tres capas juntas. Después del tratamiento alcalino, el contenido de lignina fue de 31,52 % en exotesta, 16,88 % en mesotesta y 15,32 % en endotesta. Lignina dioxano se aisló del tegumento de la semilla y la misma se redujo químicamente con NaHB4. Los espectros infrarrojos se registraron a partir de lignina dioxano, lignina dioxano reducida y de lignina de Klason de cada capa con tratamiento alcalino. Se realizaron análisis microscópicos de las capas de exotesta y mesotesta de la testa de la semilla al natural, por prueba histoquímica (prueba Wiesner) y por microscopía de fluorescencia. El análisis infrarrojo permitió observar la presencia de terminales aldehído en lignina dioxano y trazar el perfil estructural de las ligninas de Klason en capas diferentes. En el análisis microscópico con fluorescencia se identificó en la exotesta la presencia de macroesclereidas altamente lignificadas.

Competitive bonuses are commonly used to promote higher productivity in the workplace. Yet, these types of incentives could have negative spillovers on coworkers' prosocial behavior in subsequent tasks. To investigate this question, we conduct a lab-in-the- eld experiment in Ghana. In a between-subjects design, participants complete a real-effort task under a competitive, threshold, or random payment while holding payment differentials constant across treatments. Before and after, we measure prosociality through a public goods and a social value orientation game. Competition reduces prosociality when the dispersion of payments is high. However, when there is less at stake, competition does not affect prosociality.

This paper investigates the efficiency of carrot and stick policies to reduce investment in coca cultivation in rural Colombia. To measure behavioral responses to anti-drug policies, we conducted a framed field experiment with farmers living in one of the most important coca growing areas. Our experimental design allows identifying heterogeneous producer types and measuring their behavioral response to carrots and sticks. We provide an example on how knowledge on distribution types can be used to design an optimal anti-drug policy. We find that about one third of the farmers have moral costs that are high enough to deter them from investing in coca and hence, would require no external incentives. Yet destroying coca completely is prohibitively costly for two fifths of the participants who would require an extremely high compensation or risk of eradication.

The effect of pure Zn2+ and combined Zn2+ and Mn2+ supplements on the growth and ligninolytic activity of wood-rotting basidiomycetes was studied. Based on measurements of minimum inhibitory concentration and minimum decolourisation-inhibiting concentration available from cultures of Inocutis sp., Trametes versicolor and Gloeophyllum trabeum, and a comparison of such results with those obtained in previous work for P. chrysosporium and P. atropurpurascens, metal supplements were shown to inhibit fungal physiology at concentrations within the study range. Average minimum inhibitory concentration values were consistently lower for ZnSO4 than for ZnSO4/MnSO4 (2 mM Zn2+), demonstrating the antagonistic effect of the tested cations. Furthermore, because the ligninolytic system of P. atropurpurascens had shown a high tolerance to metals, its ligninolytic and germinative behaviour was compared with that of P. chrysosporium. Conidial germination was inhibited at 1 mM of Zn2+ in the two strains, whereas ex...

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New approaches for wood protection based on green technologies have increased interest in using heartwood portions of certain wood species for the effects (toxic and antioxidant properties, chelate formation, hydrophobicity) of extractives located in heartwood. This study evaluated the biological performance of heartwood of Liquidambar orientalis Mill., trees well-known for production of balsam. Heartwood specimens were subjected to soil-block decay tests based on the American Wood Protection Association standard method using two brown-rot and two white-rot fungi. Specimens were also subjected to two different laboratory termite resistance tests. Additionally, heartwood specimens were tested for mold growth and resistance to furniture beetle larvae. Laboratory fungal decay resistance tests showed that the heartwood of the tree was not resistant against the fungi tested; however, the wood was resistant against termites and furniture beetle larvae in laboratory conditions. Mold tests revealed that the wood also showed resistance to mold growth. Complete biological resistance was not achieved in this study, suggesting that heartwood extractives do not directly correspond to resistance to wood-degrading fungi.

Wood preservative properties of a solution of ZnSO4 and MnSO4 (Zn/Mn molar ratio: 2∶1), obtained by a process for household battery recycling were studied. Its effect on the growth and enzymatic activity of wood rotting basidiomycetes (Coriolus versicolor, Phanerochaete chrysosporium, Pleurotus ostreatus, Ganoderma resinaceum, Punctularia atropurpurascens, Pycnoporus sanguineous, Inonotus sp, Gymnopilus spectabilis and Gloeophyllum trabeum) was analysed, based on measurements of initial growth rate, minimum inhibitory growth and decolourisation inhibiting concentration. The study solution inhibited mycelial growth and extracellular ligninolytic activity at concentrations between 0·5 and 2 mM Zn2+, depending on species. The above results were compared with the effect of solutions of pure sulphates. Study solution inhibited mycelial growth at a lower concentration than that of pure sulphates. Wood preservative effect of the study solution was demonstrated in tests using wood substrate (small blocks ...

From 1997 to 2005, an astonishing 5200 million USD was invested to reduce cocaine production in Colombia, the world's main cocaine producer. However, little is known about the effectiveness of policies targeting coca cultivation. This paper uses a survey-based experiment to evaluate the effects of the two main policies: eradication and alternative development programs. Our results support Becker's (1968) model of crime participation and in addition shed light on other non-monetary factors that affect the coca cultivation decision: religion, legitimacy, remoteness, and poverty are found to be important. We find that coca cultivation is inelastic to increases in perceived risk and relative profit so eradication and alternative development would have a rather small effect on coca cultivation. A simple simulation exercise predicts that investing additional hundred thousand dollars in eradication decreases coca cultivation in only 1.5%. (C) 2009 Elsevier B.V. All rights reserved. (Less)

We study behavior in a search experiment where sellers receive randomized bids from a computer. At any time, sellers can accept the highest standing bid or ask for another bid at positive costs. We find that sellers stop searching earlier than theoretically optimal. Inducing a mild form of time pressure strengthens this finding in the early periods. We find no significant differences in search behavior between individuals and groups of two participants. However, there are marked gender differences. Men search significantly shorter than women, and teams of two women search much longer and recall more frequently than groups with at least one man.

According to advocates, eco-certification can improve developing country farmers’ environmental and economic performance. However, these notional benefits can be undercut by self-selection: the tendency of relatively wealthy farmers already meeting eco-certification standards to disproportionately participate. Empirical evidence on this matter is scarce. Using original farm-level survey data along with matching and difference-in-differences matching models, we analyze the producer-level effects of organic coffee certification in southeast Colombia. We find that certification improves coffee growers’ environmental performance. It significantly reduces sewage disposal in the fields and increases the adoption of organic fertilizer. However, we are not able to discern economic benefits. The return on certified production is not significantly different from that on conventional production.

Affirmative action is a subject of intense debate. Supporters point to the increased representation of women and minority groups while critics contend that affirmative action can lead to inefficiencies. In this paper we present results from two field experiments that were designed to test how applicants sort in response to affirmative action rules that favor of women. Our results suggest that the criticism of affirmative action is misplaced. We find that affirmative action does not lead to lower standards in the pool of applicants.

In order to deal with crises, organizations often bring expert leaders from outside. However, relying in an outside leader can result in decreased performance of the organization. In this paper, we use an experiment to investigate the role of identity and skills of the outside leader on the performance of the organization. Our results indicate that outside leaders are less committed than inside leaders and that group members cooperate less with an outsider than an inside leader.

The intense debate on the effectiveness of the war on drugs contrasts with the lack of empirical evidence on its impacts. To evaluate the effectiveness of control-supply policies, we use micro data from an original survey with farmers living in a coca growing area in Colombia. We find that while eradication and alternative development decrease coca supply, the elasticity of supply of these policies is rather low. The efficiency of anti-drug policies could be increased by investing more in alternative development and less in eradication. Our analysis suggests that changing people's attitudes toward coca can be a promising alternative in the fight against drugs.

Continuando con el estudio del uso de una solucion obtenida en un proceso de reciclado de baterias domesticas como preservante para madera, se establecio un primer cementerio de estacas basado en la norma EN 252, que evalua la durabilidad adquirida por probetas de Pinus taeda L. Dicha solucion es acida, contiene 32 g l-1 de Zn y 15 g l-1 de Mn como sulfatos, libre de metales pesados; en ensayos de laboratorio ha demostrado propiedades funguicidas e insecticidas especifi cos, a concentraciones menores a 3% en Zn (maxima concentracion obtenida del reciclado). A las probetas tratadas con la mencionada solucion por el metodo de celula llena, se les realizo un tratamiento posterior antilixiviante con borax al 2%, por pincelado y por celula. Se comparo la durabilidad natural y la adquirida, con dicha solucion (con o sin borax), con arseniato de cobre cromatado (CCA) a dos retenciones. A 32 meses del inicio del ensayo, las concentraciones de Zn de 3% y mayores con el borax aplicado por el metodo de celula llena son las mas efectivas. Se analizaron ademas los agentes de deterioro de madera (insectos, hongos y bacterias) presentes en las probetas. Abstract As part of the study of the application of a solution obtained from a domestic batteries recycling process as a wood preservative, a field stakes test was established to assess the acquired durability in loblolly pine (Pinus taeda L.) specimens following the internationally accepted standard EN 252. This solution is acidic, containing 32 g l-1 Zn and 15 g l-1 of Mn as sulfates and free of heavy metals; in laboratory tests the solution proved to have specific fungicidal and insecticidal properties against organisms that degrade wood, at concentrations lower than 3% Zn (the highest concentration obtained from the recycling process). The specimens treated by the full cell method with the mentioned solution were afterwards treated with 2% in borax by the full cell method and by brushing in order to prevent leaching. Natural and acquired durability are compared using different concentrations of the studied solution as well as chromated copper arsenate (CCA) at two different retention levels. At 32 months, 3 % and higher concentrations of Zn and borax applied by full cell method showed to be the most effective. Main degrading agents (insects, fungi and bacteria) found in the specimens are also described.

La madera, material natural degradable es susceptible a diversos agentesbióticos y abióticos de deterioro. Microorganismos e insectos constituyen losagentes bióticos; dentro de los primeros, los hongos de la podredumbre blancade la madera poseen la habilidad de mineralizar completamente el polímero delignina, segundo componente estructural más abundante de la madera. Estapotencialidad está basada en su sistema enzimático extracelular compuestopor diferentes tipos de enzimas (peroxidasas y oxidasas) y compuestos de bajopeso molecular. En consecuencia la madera debe ser protegida a través detratamientos con productos efectivos, habiendo una tendencia mundial aldesarrollo de productos alternativos de menor toxicidad que los existentes.El presente trabajo plantea al uso de las sales de Zn y Mn como conservantespara maderas. Se estudia su eficacia antifúngica, empleando tanto sales purascomo aquellas provenientes de un proceso de reciclado de pilas. Dichas saleshan sido utilizadas a nivel industrial, interrumpiéndo u uso en 1930 debido arazones básicamente comerciales. Se plantea su aplicac ido aldesarrollo en la Unidad de Gestión Tecnológica de la Facultad de Química deun proceso por vía hidrometalúrgica de reciclado de pi comunes y alcalinas.El mismo es simple, de bajo costo y permite el aprovechamiento de losmateriales que contienen a la vez que evita la posible contaminación queprovoca su eliminación. El producto principal del proceso es una solución ricaen Zn y Mn.Se evalúa el efecto de las mencionadas soluciones sobre la fisiología dedos especiesrepresentativas de los hongos causantes de podredumbre blanca en la madera,que poseen diferente sistema ligninolítico. Se estudia la influencia de dichosmetales en la fisiología de ambos hongos, con dos estrategias. Una global queanaliza el efecto sobre el crecimiento (desarrollomicelial y germinación deconidias) y una más específica que analiza la función inolítica (actividadenzimática de las peroxidasas y expresión de los genes que codificanmanganeso peroxidasas). Para este último punto se iden caron por primeravez las MnPs de y se caracterizaron sus genes. xiv Phane rochae te chrys os porium y Punctularia atropurpuras cens , P.atropurpurascens , Fisiologíade hong os filamentos os : e fe c to de l Zn y MnLos resultados obtenidos permiten constatar la actividad antifúngica de lasolución proveniente del proceso de reciclado, así como de la mezcla de salespuras de Zn-Mn. Inhibe el crecimiento de ambos basidiomycetes, si bienes más sensible a los metales. Durante el crecimiento sobremadera en ensayos de laboratorio se confirma el poder antifúngico.. En campo,es lixiviada de la madera, pero un segundo tratamiento con bórax impide lapérdida de los metales. A 24 meses del comienzo del en as asítratads se comparan con aquellas con CCA. A nivel del sistema ligninolítico, lasolución es inhibidora de la actividad enzimática, del mismo modo que lamezcla de sales puras de Zn y Mn. El Mn presenta en términos generales unefecto inductor de los parámetro del metabolismo estud con la excepciónde la germinación de conidios y le expresión de los genes deSe constató que tiene por lo menos 7 MnPcon altasimilaridad con MnP de otros basidiomycetes. Sus genes al igual que los deson inhibidos por el Zn, en tanto que el Mn inhibe la expresiónde los genes de P.atropurpuras cens mnp P.chrys os porium. P.atropurpuras cens P.chys os porium P.atropurpurascens

We study behavior in a search experiment where sellers receive randomized bids from a computer. At any time, sellers can accept the highest standing bid or ask for another bid at positive costs. We find that sellers stop searching earlier than theoretically optimal. Inducing a mild form of time pressure strengthens this finding in the early periods. There are marked gender differences. Men search significantly shorter than women. If subjects search in groups of two subjects, there is no difference to individual search, but teams of two women search much longer than men and recall more frequently.