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Due to the rapid growth of cities, in addition to high urban flow of goods in cities, aggravated by problems of congestion and air pollution in urban areas, there is a growing need for logistics services to be operated in a digital platform environment. This paper proposes the concept of a collaborative platform for Urban Logistics as a Service (ULaaS) and validates it through a literature review and field research based on primary databases, in-depth interviews, and surveys conducted in the Campinas city, Brazil. The analysis of collected data contributed to the validation of the proposed concept and identified modules that can generate value for the stockholders in the Campinas city: parking space reservations, shared warehousing, e-commerce deliveries and logistics services. Even though the concept is not entirely new, and some similar initiatives are found in the literature, the contribution of this work is to provide a comprehensive conceptual view of the platform. The paper also discusses a possible business model for its implementation and a preliminary canvas for a minimum viable product (MVP).

The pyrolysis of Eucalyptus globulus(EG) with different blends of high density polyethylene (HDPE) and low density polyethylene (LDPE) by thermogravimetry has been studied. ASTM-E1641-16 standard method has been used to evaluate the kinetics during the pyrolysis of the studied blends. For all feedstocks (EG, HDPE and LDPE) and blends studied, the relative content (%) of the volatile organic compound has been determined by GC–MS analysis. Different synergistic effects on the activation energy of EG blends with HDPE and LDPE have been found. EG-HDPE blends showed a minimum activation energy (Ea) (125 kJ mol−1) at the 80% EG–20% HDPE ratio, while the minimum Ea value for EG-LDPE blends was found at the 60% EG–40% LDPE ratio (135 kJ mol−1) has been identified. To test which components exert a greater synergistic effect, mixtures of HDPE and LDPE with the main components of eucalyptus (cellulose, hemicellulose and lignin) have also been studied. However, no synergistic effects on the pyrolysis of cellulose have been detected. Moreover, in hemicellulose and lignin with both types of polyethylene mixtures, a significant decrease in Ea has been appreciated. The lowest Ea values for 60% cellulose–40% HDPE (167 kJ mol−1) and 60% lignin–40% HDPE (140 kJ mol−1) has been calculated. On the other hand, minimum values for 40% cellulose–60% LDPE (166 kJ mol−1) mixture and for 40% lignin–60% LDPE (168 kJ mol−1) mixture have been detected. Thus, the decrease in both Ea and the Arrhenius pre-exponential factor on the eucalyptus-polyethylene blends to the presence of hemicellulose and lignin can be attributed. Moreover, during the co-pyrolysis of HDPE-EG mixtures, n-paraffins, ketones, phenols and sugars are the main VOCs identified. In contrast, in LDPE-EG mixtures, only n-paraffins (55%) and olefins (44%) have been identified.

Ensuring environmental and social-economic sustainability in the use of materials from lignocellulosic biomass requires their fractionation and valorization of their main components. In this work, we used Eucalyptus urograndiswood to obtain chemicals and energy. The raw material was characterized in chemical terms and then subjected to autohydrolysis under variable operating conditions to optimize the extraction of hemicellulose derivatives relative to cellulose. The kinetics of the pyrolysis process was modeled in terms of activation energy and hydrogen production. Using temperatures in the range of 180–190 °C and treatment times in the range of 15–30 min allowed more than 74.5% of all hemicellulosic components in the raw material to be selectively extracted into the liquid post-hydrolysis phase, more than 90% of all glucan to remain in the solid phase and up to 27.8% of lignin to be removed. The thermal behavior of solid fraction was examined by thermogravimetric analysis, using variable heating rates under a nitrogen atmosphere, and the activation energy can be estimated by using the Flynn-Wall-Ozawa method. Based on the results, the pyrolysis of E. urograndiscan be modeled as a first-order reaction. The activation energy (Ea) at a fractional conversion αbetween 0.3 and 0.7 was 183 to 199 KJ mol−1for the raw material, whereas that for the solid residue from autohydrolysis ranged from 179 to 186 kJ mol−1at same fractional conversion when operational temperature in autohydrolysis was upper 185 °C. Based on the results, using temperatures above 180 °C and times of 15 min or longer [i.e., operating at the (0,0) experimental point for the autohydrolysis process] in combination with degrees of conversion from 0.3 to 0.8 reduced the activation energy of the pyrolysis process in relation to the raw material by up to 12% and removed hemicellulose by more 74.5% from it. In parallel, the comparative analysis of the Eavalues and the composition of the pyrolysis gas obtained showed a negative relationship between Eaand the amount of hydrogen produced.

Intermittent rivers and ephemeral streams (IRES) may represent over half the global stream network, but their contribution to respiration and carbon dioxide (CO2) emissions is largely undetermined. In particular, little is known about the variability and drivers of respiration in IRES sediments upon rewetting, which could result in large pulses of CO2. We present a global study examining sediments from 200 dry IRES reaches spanning multiple biomes. Results from standardized assays show that mean respiration increased 32‐fold to 66‐fold upon sediment rewetting. Structural equation modeling indicates that this response was driven by sediment texture and organic matter quantity and quality, which, in turn, were influenced by climate, land use, and riparian plant cover. Our estimates suggest that respiration pulses resulting from rewetting of IRES sediments could contribute significantly to annual CO2emissions from the global stream network, with a single respiration pulse potentially increasing emission by 0.2–0.7%. As the spatial and temporal extent of IRES increases globally, our results highlight the importance of recognizing the influence of wetting‐drying cycles on respiration and CO2emissions in stream networks. Sediment respiration in intermittent rivers and ephemeral streams increases substantially in response to rewettingRespiration pulses are driven by sediment properties, which, in turn, are influenced by climate and catchment characteristicsEffects of wetting‐drying cycles on respiration and CO2emissions in stream networks need consideration in upscaling and modeling efforts

Results from retrospective studies suggest that use of neuromuscular blocking agents during general anaesthesia might be linked to postoperative pulmonary complications. We therefore aimed to assess whether the use of neuromuscular blocking agents is associated with postoperative pulmonary complications.

Stevia rebaudianaresidues composting is studied and optimized using a central composite experimental design The influence of controllable composting variables [moisture (40–70%), aeration (0.05–0.30 Lairmin−1kg−1), and time (0–50 days)] on the temperature history and the properties of the compost (pH, organic matter) produced to determine suitable composting conditions. Mass balance and emitted gases of all the composting reactors have been done. Compost with high degradation entails operating at 50 days of composting under high moisture content (70%) and aeration level with values close to 0.05 Lairmin−1kg−1. Moreover, the composting process kinetic for Stevia rebaudianaresidues has been studied. The magnitude of the kinetic parameters on the studied conditions varies among 1/42 and 1/46 for 1/K1and 0.15 and 1.6 for K2. Where 1/K1is a value that measures the affinity between microorganisms and substrate and K2depends on the composting variable optimization. Both moisture and aeration affects positively and negatively the composting process. Moreover, low effect of aeration has been found. The values of 1/K1and K2obtained showed higher values (higher degradation kinetic) under 55% moisture content and 0.30 Lairmin−1kg−1.

Perennial rivers and streams make a disproportionate contribution to global carbon (C) cycling. However, the contribution of intermittent rivers and ephemeral streams (IRES), which sometimes cease to flow and can dry completely, is largely ignored although they represent over half the global river network. Substantial amounts of terrestrial plant litter (TPL) accumulate in dry riverbeds and, upon rewetting, this material can undergo rapid microbial processing. We present the results of a global research collaboration that collected and analysed TPL from 212 dry riverbeds across major environmental gradients and climate zones. We assessed litter decomposability by quantifying the litter carbon-to-nitrogen ratio and oxygen (O2) consumption in standardized assays and estimated the potential short-term CO2emissions during rewetting events. Aridity, cover of riparian vegetation, channel width and dry-phase duration explained most variability in the quantity and decomposability of plant litter in IRES. Our estimates indicate that a single pulse of CO2emission upon litter rewetting contributes up to 10% of the daily CO2emission from perennial rivers and stream, particularly in temperate climates. This indicates that the contributions of IRES should be included in global C-cycling assessments. Rewetting of plant litter accumulated in dry riverbeds releases pulses of CO2, reveals a global analysis of intermittent rivers and ephemeral streams.

ABSTRACTThis paper presents the results of numerical and experimental investigations on the force coefficients and Strouhal numbers of circular segments considering different corner angles or chord to sagitta ratios. The research is motivated because these geometries are becoming increasingly popular in several engineering disciplines. The so-called D-section (semi-circular cylinder with a corner angle of ) has been experimentally studied in the past, since it is a galloping prone geometry. However, there is a lack of research for cases with different corner angles, and the numerical investigations related to this topic are particularly scarce. In this work, a 2D Unsteady Reynolds Averaged Navier–Stokes approach has been adopted aiming to study the circular segments at the sub-critical regime, considering corner angles from to , and the flow parallel to the rectilinear side. These sections were found to be particularly challenging since they present massive flow separation on the rectilinear side, alongside the inherent difficulties related to modeling the flow along curved surfaces at high Reynolds numbers. The impact of introducing low-Reynolds-number and curvature corrections in the SST turbulence model and the performance of the Transition SST model have been extensively studied.

Analizar la trombosis de rama en el tratamiento de aneurisma de aorta abdominal (EVAR) en nuestra serie y su relación con factores de riesgo predisponentes.

Comparar los resultados del sellado distal del EVAR en ilíaca externa (IE) mediante ramificación ilíaca frente a la exclusión de la arteria hipogástrica.

El pie diabético es una entidad clínica causante de una importante morbimortalidad en nuestro medio. En 2014, la Society of Vascular Surgery propuso una nueva clasificación que estima el riesgo de amputación para miembros inferiores e incluye a pacientes diabéticos.

Background/Objectives:: Enteral feeding will induce remission in as many as 80–90% of compliant patients with active Crohn’s disease (CD), but its method of action remains uncertain. This study was designed to examine its effects on the colonic microbiome. Methods/Subjects:: Healthy volunteers and patients with CD followed a regimen confined to enteral feeds alone for 1 or 2 weeks, respectively. Chemicals excreted on breath or in faeces were characterised at the start and at the end of the feeding period by gas chromatography/mass spectrometry. Results:: One week of feeding in healthy volunteers caused significant changes in stool colour and deterioration in breath odour, together with increased excretion of phenol and indoles on the breath. Feeding for 2 weeks in patients with CD produced significant improvements in symptoms and a decrease in the concentration of C-reactive protein. The faecal concentrations of microbial products, including short-chain fatty acids (SCFAs), and potentially toxic substances, including 1-propanol, 1-butanol and the methyl and ethyl esters of SCFAs, showed significant falls. Conclusions:: A significant change occurs in the production of microbial metabolites after enteral feeding in both healthy volunteers and patients with CD. Many of those detected in CD are toxic and may feasibly lead to the immunological attack on the gut microbiota, which is characteristic of inflammatory bowel disease. The reduction in the production of such metabolites after enteral feeding may be the reason for its effectiveness in CD.

Tras estudios propios referentes a la evolución del sellado distal modificamos la actitud en el sellado de las endoprótesis de aorta abdominal: sellando en iliacas primitivas (IP) si eran menores de 16mm de diámetro y en iliacas externas (IE) si eran mayores. El objetivo del trabajo es valorar los efectos del cambio de criterio en el sellado distal.

Articles report that the sulphate reducing bacteria (SRB) are the main micro-organisms related to cases of corrosion. They reduce the sulfate ion resulting in the production of sulfide, disulfide and hydrogen sulfide, potential agents of corrosion of ferrous materials. This study investigated the action of sulfate-reducing bacteria on corrosion test specimens with welded joint of API 5L X80 steel in the presence of seawater. The samples were exposed to sea and sterilized water was then added to BRS. Microorganisms were quantified periodically calculated the corrosion rate and weight loss, and the surfaces of the samples analyzed by light microscopy.

Human and mouse respiratory tracts show anatomical and physiological differences, which will benefit from alternative experimental models for studying many respiratory diseases. Pig has been recognized as a valuable biomedical model, in particular for lung transplantation or pathologies such as cystic fibrosis and influenza infection. However, there is a lack of knowledge about the porcine respiratory immune system. Here we segregated and studied six populations of pig lung dendritic cells (DCs)/macrophages (Mθs) as follows: conventional DCs (cDC) 1 and cDC2, inflammatory monocyte-derived DCs (moDCs), monocyte-derived Mθs, and interstitial and alveolar Mθs. The three DC subsets present migratory and naive T-cell stimulation capacities. As observed in human and mice, porcine cDC1 and cDC2 were able to induce T-helper (Th)1 and Th2 responses, respectively. Interestingly, porcine moDCs increased in the lung upon influenza infection, as observed in the mouse model. Pig cDC2 shared some characteristics observed in human but not in mice, such as the expression of FCɛRIα and Langerin, and an intra-epithelial localization. This work, by unraveling the extended similarities of the porcine and human lung DC/Mθ networks, highlights the relevance of pig, both as an exploratory model of DC/Mθ functions and as a model for human inflammatory lung pathologies.

Aunque las unidades de dolor torácico (UDT) permiten la estratificación y atención apropiada de los pacientes con dolor de pecho, en Colombia el desarrollo e implementación sistemática y estandarizada de este proceso de atención es escaso.

El objetivo es comparar la planificación del tratamiento endovascular de aneurismas de aorta abdominal (endovascular aneurysm repair[EVAR]) realizada mediante estudio tridimensional con la basada en tomografía computarizada (TC) y aortografía centimetrada. Analizar el impacto de la variabilidad de las mediciones en los resultados.

Los procedimientos restauradores indirectos son comunes en la clínica diaria actual. Se debe tener cuidado especial en la cementación, pues la gran mayoría de los fracasos ocurren en la interfase diente/restauración. Por esto es indispensable un adecuado tratamiento de superficie de la restauración para lograr una adhesión óptima a la superficie dentaria.

It is essential from the public health point of view, that the Mexican regulatory agencies implement a monitoring surveillance program that not only uses preliminary screening methods for the determination of clenbuterol, but also uses confirmatory methods such as MS-MS techniques. Thus, the aim of this work was to monitor the presence of clenbuterol residues in bovine meat muscle collected from the local market. From 50 bovine meat samples analyzed by the ELISA test, 6 (12%) presented clenbuterol residues from 3.06 to 6.12 μg/kg, 13 (26%) from 0.5 to 1.83 μg/kg, 24 (48%) from 0.1 to 0.5 μg/kg and only 7 (14%) were below the limit of detection (LOD) of 0.1 μg/kg. The six samples with the highest clenbuterol residues were subjected to GC-MS-MS for confirmation. The results showed that clenbuterol was illegally used as a bovine growth promoter.El objetivo del presente trabajo fue determinar y confirmar la presencia de residuos de clenbuterol en carne de bovino comercializada en el noroeste de Mexico. De un total de 50 muestras de carne de bovino obtenidas del mercado y analizadas por inmunoensayo especifico ligado a enzima (ELISA), 6 muestras (12%) presentaron residuos de clenbuterol en un rango de 3,06 a 6,12 μg/kg, 13 muestras (26%) de 0,5 a 1,83 μg/kg, 24 muestras (48%) de 0,1 a 0,5 μg/kg y solo 7 muestras (14%) se encontraron por debajo del limite de deteccion (LOD) de 0,1 μg/kg del ensayo ELISA. Las 6 muestras que presentaron los mas altos residuos de clenbuterol, fueron sujetas a confirmacion por medio de cromatografia de gases acoplada a un detector selectivo de masas-masas (GC-MS-MS). Los resultados encontrados confirmaron la presencia de clenbuterol, el cual fue ilegalmente utilizado como promotor de crecimiento de bovinos.Palabras clave: Residuos de clenbuterol, carne de bovino

Juvenile myoclonic epilepsy (JME) accounts for 3 to 12% of all epilepsies. In 2004, the GENESS Consortium demonstrated four missense mutations in Myoclonin1/EFHC1of chromosome 6p12.1 segregating in 20% of Hispanic families with JME.

This work investigated the deformation and fracture behavior of polypropylene–ethylene vinyl alcohol (PP/EVOH) blends compatibilized with ionomer Zn2+. Uniaxial tensile tests and quasistatic fracture experiments were performed for neat PP and for 10 and 20 wt % EVOH blends with different ionomer contents. The addition of EVOH copolymer to PP led to an increase in the Young's modulus whereas the yield strength was decreased with the EVOH content as a consequence of the higher stiffness of EVOH and the poor interfacial adhesion between PP and EVOH, respectively. Furthermore, the incorporation of EVOH into PP promoted stable crack growth. Neat PP displayed nonlinear load‐displacement behavior with some amount of slow crack growth preceding unstable brittle fracture, whereas most PP/EVOH blends exhibited “pseudostable” fracture characterized by slow crack growth that could not be externally controlled. All blends exhibited lower resistance to crack initiation than PP but the fracture propagation resistance was significantly improved. For 10 wt % EVOH blends, the resistance to crack initiation was roughly constant with the ionomer content up to 5%, then it increased with the further addition of compatibilizer. Conversely, for 20 wt % EVOH blends, the resistance to crack initiation appeared to be independent of the ionomer content. The better resistance to crack initiation exhibited by the 10 wt % EVOH blends could be attributed to a higher level of compatibilization in these blends. By contrast, 20 wt % EVOH blends with ≤2% ionomer content showed completely stable crack growth. In addition, J–R curves and valid plane strain fracture toughness values for these blends could also be determined. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1271–1279, 2005

This paper presents polarographic and voltammetric studies on the electroreduction of 2,6‐dimethoxy‐4‐chloro‐1,3,5‐triazine on mercury electrodes in aqueous solutions and in the acidity range 2 M H2SO4to pH 7. Above pH 6.5 no signals were obtained. In both DC and DP polarography and voltammetry, one or two partially overlapped reduction waves were observed, depending on the pH of the medium. The overall process corresponded to a four‐electron irreversible reduction. In strongly acidic media (pH<4.5) the protonated reactant was reduced through a two‐electron process to give a dechlorinated molecule that is subsequentely reduced at the potentials of the second wave. It was concluded that the reduction of the chlorinated s‐triazine rings seems to occur through the reductive cleavage of the chlorine irrespective of the nature of the groups bonded to the ring in positions 2, 6.

A detailed analysis of three species–rich ecosystem food webs has shown that they display skewed distributions of connections. Such graphs of interaction are, in fact, shared by a number of biological and technological networks, which have been shown to display a very high homeostasis against random removals of nodes. Here, we analyse the responses of these ecological graphs to both random and selective perturbations (directed against the most–connected species). Our results suggest that ecological networks are very robust against random removals but can be extremely fragile when selective attacks are used. These observations have important consequences for biodiversity dynamics and conservation issues, current estimations of extinction rates and the relevance and definition of keystone species.

The structure and regulation of the microsomal glutathione S-transferase gene (MGST1) are considerably more complex than originally perceived to be. The MGST1 gene has two alternative first exons and is located in the 12p13.1-13.2 region. Two other potential first exons were determined to be nonfunctional. The region between the functional first exons cannot direct transcription. Thus, one common promoter element directing transcription exists, and RNA splicing occurs such that only one of the first exons (containing only untranslated mRNA) is incorporated into each mRNA species with common downstream exons. MGST1 expression and regulation are therefore similar to those of other hepatic xenobiotic handling enzymes, which also produce mRNA species differing only in the 5'-untranslated regions to yield identical proteins. MGST1 was previously considered a "housekeeping" gene, as non-oxidant inducers had little effect on activity. However, the promoter region immediately upstream of the dominant first exon transcriptionally responds to oxidative stress. In this respect, MGST1 is similar to glutathione peroxidases that also transcriptionally respond to oxidative stress. The discovery that MGST1 utilizes alternative first exon splicing eliminates a problem with the first description of MGST1 cDNA in that it appeared that MGST1 expression was in violation of the ribosomal scanning model. The identification that the first exon originally noted is in fact a minor alternative first exon far downstream of the primary first exon eliminates this conundrum.

A strictly factor-dependent cell line (UCSD/AML1) was established from a patient with the syndrome of multilineage acute leukemia with high platelets. The patient's cells and the cell line karyotype were 45,XX,- 7,t(3;3)(q21;q26), typical of the syndrome of acute leukemia with high platelets. The cell line expresses CD34, CD7, TdT, and myeloid (CD13, CD14, CD33) and megakaryocyte/platelet (CD36, CD41, CD42b, CDw49b) antigens. In short-term culture, UCSD/AML1 cells proliferate in response to interleukin-3 (IL-3), IL-4, IL-6, macrophage colony- stimulating factor (M-CSF), and granulocyte-macrophage CSF (GM-CSF), but not IL-1, IL-2, IL-5, or G-CSF. In long-term culture, proliferation can be sustained by GM-CSF, IL-6, or M-CSF. When maintained in GM-CSF, a small percentage of cells form multinucleated megakaryocyte-like giant cells. Culture with GM-CSF combined with IL-6, but not with IL-6 alone, increased giant cell formation fourfold to sevenfold. IL-6 alone or in combination with GM-CSF increased expression of platelet-related antigens. In contrast, culture with phorbol ester induced formation of macrophage-like cells. UCSD/AML1 is the first human acute nonlymphocytic leukemia cell line established from a patient with an acute leukemia syndrome associated with a specific chromosome abnormality.

Summary Estrogens retard bone loss after menopause and constitute the most logical therapy for the prevention of postmenopausal osteoporosis. Estrogens are contraindicated in some circumstances and some postmenopausal women are unwilling to accept them. We have used ADFR therapy as an alternative in the prevention of postmenopausal bone loss. One hundred women in the early postmenopausal period (6–24 months since the last menses) were introduced into the study. 50 were treated with placebo and 50 were treated with ADFR therapy (phosphorus 1.5 gr/day during 3 days, followed by SCT 100 UI/day during 10 days and calcium 1 gr/day). After 77 days without any therapy we repeated the cycles every 3 months. Bone mass was evaluated at the beginning and at 3, 6, 12 and 18 months by dual-photon absorptionmetry lumbar spine. In the control group, the mean spinal BMD decreased 7.31% after 12 months and 6.16% after 18 months (p>0.05). The ADFR group only had a mean spinal BMD decrease of 3.79% and 1.1% after 12 and 18 months respectively (NS). Bone loss was greater in control than in ADFR group after 12 and 18 months (p<0.05 at both times). We conclude that phosphorus and calcitonin like ADFR therapy may be a useful alternative to estrogen for the prevention of accelerated bone loss after menopause.

The Andean farmer conserves and maintains the existing genetic diversity of potato cultivars by means of clonal propagation of tubers. However, surveys of traditional farms showed that botanical seed propagation was used for disease elimination, stock rejuvenation and the creation of new cultivars. Electrophoretic surveys based on 542 tubers collected from 18 markets sampled in the Cusco area disclosed a total of 229 different cultivars from diploid, triploid and tetraploid forms of Solanum tuberosum L. These could be classified by isozyme cluster analysis into four major groups and six minor groups. However, they did not agree with groups based on flesh or skin color. It is therefore concluded that all genotypes belong to a single, large gene pool with considerable gene flow between cultivars of different groups. When the samples were grouped by the three most common tuber skin colors, namely red/pink (‘Q'ompis type’), purple (‘Yana Imilla’ type), and yellowish/brown (‘Yuraq Kusi’ type), similar allozymes were observed in all three classes. The structure of the isozymic phenotypes within each group indicate that they may have been derived as segregants after outcrossing of diverse parental types. In order to provide further evidence for the origin of new types by hybridization, two segregating diploid progenies were generated by crossing purple by yellow skin types. In the resulting F1, most of the tuber phenotypes observed in the Andean varieties were reproduced in these crosses. It can be concluded that the Andean potatoes form a large and plastic gene pool amplified and renovated by outcrossing followed in some cases by human selection of desirable phenotypes.

The electrooxodation of diethyl 1,4‐dihydro‐2,4,6‐trimethyl‐3,5‐pyridinedicarboxylate (DTP) in ethanol/water solutions on a glassy carbon electrode has been studied by linear‐sweep cyclic voltammetry. Convolution voltammetry was used to analyze the I‐Ecurves. From the experimental results it was concluded that in acidic media, the rate‐determining step, r.d.s., was the deprotonation of the radical cation formed after the first one‐electron transfer. In basic media, the mechanism consisted of a DISP1 scheme in which r.d.s. is the uptake of an H+ion by both the OH−ion and the basic components of the buffer. The relative rate constant of the carbonate ion with respect to the OH−is calculated.

The electrooxidation of the bactericide and fungicide agent 2‐mercaptopyridine‐N‐oxide (PySH), or pyrithione, was investigated by using mercury (Hg), glassy carbon (GCE), plastic formed carbon (PFCE) and paste (CPE) electrodes. From controlled‐potential electrolyses or chronoamperometric measurements, the number of electrons involved in the oxidation processes was found to be close to unity in all cases. Voltammetric measurements showed that the irreversibility of the electron transfer must be related to the roughness and ordering in the surface of the electrode material: as the amorphous character of the carbon electrode was increased, the transfer appeared faster. Other effects as the O/C ratio or the removal of impurities can also influence the reversibility of the transfer. The rate constants of the electron transfers at zero potential were obtained. In addition, the extension of the adsorptive oxidation decreased when the amorphous character of the electrode was increased, but the Gibbs free enthalpy of this process did not vary from one electrode to another nor for the Hg electrode.

Electrical conductivity measurements were carried out in avocado fruit during storage under various conditions and after transferring to 20°C. Refrigerated storage trials were carried out under normal atmosphere and modified atmosphere at 4°C and 6°C. In parallel with the electrical parameter, respiration intensity and pulp firmness were obtained to estimate the time course of ripening in avocado. In fruits transferred to 20°C, a curve showing a maximum was found. This curve is tentatively explained by an increase in release of ions due to biochemical changes occurring during ripening. Thus, electrical conductivity seems to be a suitable index of avocado condition during cold-storage and ripening. This research work has enabled the authors to define a threshold of conductivity (0.24 S/m) that indicates the limiting value for fruit stored at non-injurious temperatures and subsequently transferred to 20°C for marketing. Copyright 1994, 1999 Academic Press

For the violent collisions of 27 MeV/nucleon40Ar with Ag, coincidence measurements have been made between heavy residues and intermediate mass fragments (3?Z?14) or light charged particles. From the analysis of the correlation between heavy residues (mass and velocity) and intermediate mass fragments, the main characteristics of the dominant mechanisms, fusion and partially damped collisions preceded or accompanied by a preequilibrium emission, are presented. Balances concerning mean values of parallel linear momentum, mass and atomic number, are established and confirm that a complete description of violent collisions was obtained. Then thermalization is discussed, first in terms of excitation energies derived from kinematics between heavy residues and intermediate mass fragments, and secondly in terms of initial temperature estimates derived from light charged particle spectra. Very hot nuclei (T?5.7–6.6 MeV) are produced over a large impact parameter range from very central collisions to medium peripheral ones. Various experimental results are compared to predictions obtained with semi-classical calculations (Landau-Vlasov equation). From their good agreement one may conclude that, depending on the impact parameter, thermal equilibrium is achieved within 4–10×10-22 s.