Bullying, envolvimento parental e percurso curricular: um estudo com alunos do 3º ciclo numa escola rural da Região Autónoma da Madeira

A investigação sobre o bullying reconhece que este fenómeno está disseminado nas relações estabelecidas pelos alunos com o grupo de pares no ambiente escolar e o entendimento dos mecanismos subjacentes ao desenvolvimento das ações de bullying deve integrar uma perspetiva sistémica. Um aluno está a ser vítima de bullying quando este encontra-se exposto, repetidamente e ao longo do tempo a ações negativas realizadas por um ou mais estudantes causando dor e sofrimento na vítima. O envolvimento parental na escola pode beneficiar os alunos, os professores e as famílias correlacionando-se positivamente com o desempenho académico dos alunos. A finalidade do currículo escolar consiste na aquisição de competências e conhecimento fundamentais para o desenvolvimento das dimensões cognitivas, emocionais e sociais dos discentes. O presente estudo pretende analisar a relação entre os comportamentos de bullying na escola, o envolvimento parental na escola e o percurso curricular dos alunos de uma escola pública da Região Autónoma da Madeira (RAM). A amostra é constituída por 270 alunos do 3º ciclo do ensino básico, com idades compreendidas entre os 12 e os 18 anos. Para a avaliação dos fenómenos foram utilizados métodos mistos de investigação. Para a recolha de dados foram utilizados o Questionário para o Estudo da Violência entre os Pares de Freire, Simão, e Ferreira (2006) e as Escalas de Sucesso Escolar de Gouveia (2008). Na análise dos dados foram utilizadas as correlações, a regressão múltipla, e a análise de conteúdo. Os resultados obtidos indicam que a prevalência do bullying na escola é relativamente baixa e que os rapazes são maioritariamente as vítimas e os agressores. Os resultados indicam que os alunos com um maior envolvimento em comportamentos de bullying apresentam perceções elevadas de envolvimento educativo parental e apenas os alunos agressores apresentam perceções reduzidas de apoio parental emocional. Verificou-se também que o envolvimento parental pode ser considerado um preditor do envolvimento dos alunos em comportamentos de bullying assim como as retenções escolares não predizem o envolvimento dos alunos neste tipo de comportamentos. Os resultados deste estudo fornecem pistas relevantes para a intervenção no fenómeno do bullying na escola integrando as escolas, as famílias, os alunos e as comunidades.

Práticas pedagógicas na utilização de quadros interativos multimédia

Mudança, rutura, inovação – estas são algumas das principais demandas da realidade do século XXI, num mundo que avança vertiginosamente face a um futuro incerto. A noção de proficiência enquadra-se em praticamente todos os cenários com que o ser humano se depara. Em temos educacionais urge adequar as evoluções tecnológicas, que controlam a maioria das tarefas do quotidiano, aos processos educativos implementados nas escolas, bem como na vida de cada indivíduo como ser construtor do seu saber; desta forma, alguns requisitos tornam-se prementes face à construção de um conhecimento válido e universal. O modo como as tecnologias assumiram um papel preponderante na maioria dos sistemas educativos postula estudos empíricos que apresentam uma perceção da articulação entre as tecnologias e os atuais métodos de ensino-aprendizagem. A presente investigação propõe-se analisar uma ferramenta cognitiva da atualidade – o Quadro Interativo – no que concerne às estratégias e práticas pedagógicas a ela associadas. Este estudo baseia-se numa metodologia preponderantemente qualitativa cujo objetivo consiste em reunir os dados mais recentes relacionados com o tema, incidindo no uso de técnicas e instrumentos de índole qualitativa nomeadamente observação, entrevistas e análise documental. Não se pretende tirar ilações ou generalizações dos factos, sendo que, a investigação visa estudar casos nos quais se encetam práticas pedagógicas com recurso às novas tecnologias, em particular ao Quadro Interativo, numa perspetiva de rutura paradigmática, averiguando em que medida estas práticas representam cenários inovadores. Foi possível apurar que a tecnologia não é sinónimo de inovação pedagógica uma vez que os processos de ensino estão presentes nas observações da investigadora; a tecnologia é usada na abordagem e esclarecimento de conteúdos curriculares porém, contribui para a retenção de informação e a aquisição do conhecimento inerente aos conteúdos referidos ao incrementar a motivação dos alunos.

Marketing de relacionamento em um provedor de internet: um estudo comparativo que considera a visão gerencial e a percepção dos clientes

The current paper aims at analyzing customer retention in Internet provider services. For this study, we sought to understand what are the client's expectations regarding the services available and compare them with management perception in relation to the use of those services. Identifying the coherence level between the two points of view, management and client, it is possible to pinpoint how service is assessed in real conditions. Then, from this point on, a new vision can be implemented on available services, and new customer service strategies aiming at best serving to their expectation and need, can be rethought. The exploratory research was utilized. It was based on case study, and quantitative and qualitative methods were used. The quantitative method was done by applying the cluster technique with six variables of control derived from the six main services, whose definition was done through qualitative survey of the internal management team. Then, an structured interview with 443 clients, from a probabilistic sample of 800 costumers. The total number of active clients of the internet provider is of 10.677. Client perception in relation to services varied, if compared with the four services that were under the managerial metric method, this comparison showed a more positive evaluation than the real use of the service. Thus, it was observed that the value of each service available for the client depends on his/her perception of it, regardless of using or not the offered service. As a result, it is possible to understand which services offered by the company under study effectively contribute to a good client-company relationship, and the upkeep of those clients

Qualidade do ar interior e conforto térmico : um estudo em espaços de estacionamento em Natal/RN

The recent tendency to utilize parking lots for other purposes has demonstrated that more time has been spent by visitors, mainly in great cities. Therefore, this paper investigates the thermal comfort and the air quality indoors in areas specifically used as parking lots by analyzing the direct relation between such environments and vehicular pollution. The thermal comfort and the quality of air indoors in parking lots with different architectonic typology (ground-floor and underground) are also studied, aiming to contribute to the proposition of suitable new areas designated to human usage. Field research was done, in two distinct periods within different weather conditions (January and July) in, two naturally cooled, parking lots located in Natal - RN. The internal environment agents were measured by using tools for air temperature, humidity, speed and direction; interviews with employees and visitors and chemical analysis through appropriate tools to analyze specific material, carbon monoxide and ozone. The results showed that chemical agents densely concentrate mostly in the closed parking space, aggravated by weather conditions, which dissatisfied the visitors. Still, it was shown that architectonic typology, alongside topographical aspects compromise internal environmental conditions, which increases the retention of pollution, leading to dissatisfactory thermal comfort levels and becoming less suitable for usage by visitors considering air and thermal comfort aspects. Consequently, they are not suitable for human stay due to the poor quality of the indoor air

Genotoxicidade e composição do material particulado emitido pela queima de Biomassa: um estudo de caso em Tangará da Serra, Região da Amazônia Brasileira

Tangara da Serra is located on southwestern Mato Grosso and is found to be on the route of pollutants dispersion originated in the Legal Amazon s deforestation area. This region has also a wide area of sugarcane culture, setting this site quite exposed to atmospheric pollutants. The objective of this work was to evaluate the genotoxicity of three different concentrations of organic particulate matter which was collected from August through December / 2008 in Tangara da Serra, using micronucleus test in Tradescantia pallida (Trad-MCN). The levels of particulate matter less than 10μm (MP10) and black carbon (BC) collected on the Teflon and polycarbonate filters were determined as well. Also, the alkanes and polycyclic aromatic hydrocarbons (PAHs) were identified and quantified on the samples from the burning period by gas chromatography detector with flame ionization detection (GC-FID). The results from the analyzing of alkanes indicate an antropic influence. Among the PAHs, the retene was the one found on the higher quantity and it is an indicator of biomass burning. The compounds indene(1,2,3-cd)pyrene and benzo(k)fluoranthene were identified on the samples and are considered to be potentially mutagenic and carcinogenic. By using Trad-MCN, it was observed a significant increase on the micronucleus frequency during the burning period, and this fact can be related to the mutagenic PAHs which were found on such extracts. When the period of less burnings is analyzed and compared to the negative control group, it was noted that there was no significant difference on the micronuclei rate. On the other hand, when the higher burning period is analyzed, statistically significant differences were evident. This study showed that the Trad-MCN was sensible and efficient on evaluating the genotoxicity potencial of organic matter from biomass burning, and also, emphasizes the importance of performing a chemical composition analysis in order to achieve a complete diagnosis on environmental risk control

Influência do lodo de ETE na massa para fabricação de cerâmica vermelha

The WTP produce many kinds of residue on your treatment stages, but the sludge is the more problematic from the final disposition point view. The actual rate of residue production deriving from technological evolution and the crescent population needs prevents the subtle equilibrium generation between consumption and recycling/reuse, creating problems of pollution resulting from inappropriate management of residues. Thus, is necessary achieve a new equilibrium between the grow from raw materials and energy and the residue generation. This equilibrium should be achieved by technical and economic feasibility of environmental supported models through recycling and reuse. The red ceramic industry stand out in residue absorption question as raw material due their clay mass heterogeneity, constituted by clay minerals and non-clay minerals with wide mineralogical variation, allowing residue inclusion which act like plastic or non-plastic materials, contributing to retain heavy metals contained in residues in the vitreous mass formed during the burning of the ceramic bodies. This work propose the study of the influence of incorporation of 25 wt.% sludge from wastewater treatment plant, according preliminary results, in the mass to produce ceramic bodies. The raw materials was characterized through chemical composition analyses by XRF, mineralogical analyses by XRD, thermal analyses by TG and DTA, Atterberg limits and thermodilatometry. Subsequently was composed the mass with 75 wt.% of clay and 25 wt.% of dried wastewater sludge from UFRN WWTP. Samples with 6,0 x 2,0 x 0,5 cm was produced with unidirectional compacting under pressure of 20MPa and burned in temperatures between 950 and 1,200ºC. After fired, the ceramic bodies have been submitted to physical and mechanical analyses through the measure of firing shrinkage, water absorption, density, apparent porosity and flexural strength; crystallographic analyses through XRD and microstructure analyses by SEM. The technological properties obtained was satisfactory to production of roof tiles with 25 wt.% at 1,200 ºC, but the production of others products at lower temperatures was not feasible

Influência do número de refundições da liga Ni-Cr-Mo-Ti sobre as propriedades de próteses metalocerâmicas

A frequently encountered difficulty in oral prosthetics is associated with the loss of metallic alloys during the melting stage of the production of metal-ceramic replacement systems. Remelting such materials could impar their use in oral rehabilitation due to loss in esthetics, as well as in the chemical, physical, electrochemical and mechanical properties. Nowadays, the Ni-Cr-Mo-Ti alloy is widely used in metal-ceramic systems. Manufacturers state that this material can be remelted without significant alterations in its behavior, however little has been established as to the changes in the performance of this alloy after successive remelting, which is common practice in oral prosthetics. Therefore, the objective of this study was to evaluate possible changes in the esthetics and associated properties of metalceramic samples consisting of Ni-Cr-Mo-Ti and dental porcelain. Three to five remelting steps were carried out. The results revealed that Ni-Cr-Mo-Ti can be safely used even after three remelting steps. Further remelting significantly affect the characteristics of the alloys and should not be recommended for the manufacture of metal-ceramic systems

Aproveitamento de resíduos minerais na formulação de argamassas para a construção civil

Current environmental concerns include the excessive consumption and inefficient use of non-renewable natural resources. The construction industry is considered one of the largest consumers of natural raw materials, significantly contributing to the environmental degradation of the planet. The use of calcareous quarry (RPPC) and porcelain tile polishing residues (RPP) as partial replacements of the cement in mortars is an interesting alternative to minimize the exploration of considerably large amounts of natural resources. The present study aimed at investigating the properties of fresh and hardened mortars produced using residues to replace cement. The residues used were fully characterized to determine their specific mass, unitary mass, particle size distribution and morphology, and composition. The performance of the mortars was compared to that of reference compositions, prepared without residues. A total of 18 compositions were prepared, 16 using residues and 2 reference ones. The mortars were prepared using Portland CP II F 32 cement, CH I hydrated lime, river sand and tap water. The compositions of the mortars were 1:1:6 and 1:0.5:4.5 (vol%), and water to cement ratios of 1.87 and 1.45 were used, respectively. The mortars in the fresh state were evaluated by consistency index, water retention, density of mass and incorporated air content tests. In their hardened state, the mortars were evaluated by apparent mass density, modulus of elasticity, flexural tensile strength, compressive strength and water absorption by capillarity. The mortars were also analyzed by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction and fluorescence. Finally, they were classified according to NBR 13281 standards. The mortars prepared using residues partially replacing the cement exhibited lower modulus of elasticity compared to the reference compositions, thus improving the performance in their intended use. On the downside, the water absorption by capillarity was affected by the presence of residues and both the tensile and compressive strength were reduced. However, from the overall standpoint, the replacement of cement by calcareous quarry or porcelain tile polishing residues did not result in significant changes in the properties of the mortars. Therefore, compositions containing these residues can be used in the construction industry

Desenvolvimento de um protótipo para análise dinâmica da dureza de superfícies metálicas

In this paper we developed a prototype for dynamic and quantitative analysis of the hardness of metal surfaces by penetration tests. It consists of a micro-indenter which is driven by a gear system driven by three-rectified. The sample to be tested is placed on a table that contains a load cell that measures the deformation in the sample during the penetration of micro-indenter. With this prototype it is possible to measure the elastic deformation of the material obtained by calculating the depth of penetration in the sample from the difference of turns between the start of load application to the application of the load test and return the indenter until the complete termination of load application. To determine the hardness was used to measure the depth of plastic deformation. We used 7 types of steel trade to test the apparatus. There was a dispersion of less than 10% for five measurements made on each sample and a good agreement with the values of firmness provided by the manufacturers.

Análise mecânica e microestrutural das ligas de cobalto-cromo de uso odontológico após sucessivas refundições

The cobalt-chromium alloy is extensively used in the Odontology for the confection of metallic scaffolding in partial removable denture. During the last few years, it has been reported an increasing number of premature imperfections, with a few months of prosthesis use. The manufacture of these components is made in prosthetic laboratories and normally involves recasting, using parts of casting alloy and parts of virgin alloy. Therefore, the objective of the present study was to analyze the mechanical properties of a commercial cobalt-chromium alloy of odontological use after successive recasting, searching information to guide the dental prosthesis laboratories in the correct manipulation of the cobalt-chromium alloy in the process of casting and the possible limits of recasting in the mechanical properties of this material. Seven sample groups were confectioned, each one containing five test bodies, divided in the following way: G1: casting only with virgin alloy; G2: casting with 50% of the alloy of the G1 + 50% of virgin alloy; G3: casting with 50% of the alloy of the G2 + 50% of virgin alloy; G4: casting with 50% of the alloy of the G3 + 50% of virgin alloy; G5: 50% of alloy of the G4 + 50% of virgin alloy; G6: 50% of alloy of the G5 + 50% of virgin alloy and finally the G7, only with recasting alloy. The modifications in the mechanical behavior of the alloy were evaluated. Moreover, it was carried the micro structural characterization of the material by optic and electronic scanning microscopy, and X ray diffraction.and fluorescence looking into the correlatation of the mechanical alterations with structural modifications of the material caused by successive recasting process. Generally the results showed alterations in the fracture energy of the alloy after successive recasting, resulting mainly of the increasing presence of pores and large voids, characteristic of the casting material. Thus, the interpretation of the results showed that the material did not reveal significant differences with respect to the tensile strength or elastic limit, as a function of successive recasting. The elastic modulus increased from the third recasting cycle on, indicating that the material can be recast only twice. The fracture energy of the material decreased, as the number of recasting cycles increased. With respect to the microhardness, the statistical analyses showedno significant differences. Electronic scanning microscopy revealed the presence of imperfections and defects, resulting of the recasting process. X ray diffraction and fluorescence did not show alterations in the composition of the alloy or the formation of crystalline phases between the analyzed groups. The optical micrographs showed an increasing number of voids and porosity as the material was recast. Therefore, the general conclusion of this study is that the successive recasting of of Co-Cr alloys affects the mechanical properties of the material, consequently leading to the failure of the prosthetic work. Based on the results, the best recommendadition is that the use of the material should be limited to two recasting cycles

Síntese, aplicação e avaliação do efeito do teor de fósforo da celulose fosfatada em argamassa de alvenaria com aditivo comercial a base de hidroxi-etil-metil celulose (HEMC)

Generally, cellulose ethers improves mortar properties such as water retention, workability and setting time, along with adherence to the substrate. However, a major disadvantage of the addition of cellulose ethers in mortars is the delay in hydration of the cement. In this paper a cellulose phosphate (Cp) was synthesized water soluble and has been evaluated the effect of their incorporation into mortar based on Portland cement. Cellulose phosphate obtained was characterized by spectrophotometry Fourier transform infrared (FTIR), X-ray diffraction (XRD), elemental analysis and scanning electron microscopy (SEM). Mortar compositions were formulated with varying phosphorus content in cellulose and cellulose phosphate concentrations, when used in partial or total replacement of the commercial additive based hydroxyethyl methyl cellulose (HEMC). The mortars formulated with additives were prepared and characterized by: testing in the fresh state (consistency index, water retention, bulk density and air content incorporated) and in the hardened state (absorption by capillarity, density, flexural and compression strength). In mixtures the proportion of sand:cement of 1:5 (v / v) and factor a / c = 1.31 and water were held constant. Overall, the results showed that the celluloses phosphates employed in mortars added acted significantly when partially substituting the commercial additive. With regard to consistency index, water retention and bulk density in the fresh state and absorption by capillarity and bulk density apparent in the hardened state, showed no appreciable differences as compared to the commercial additive. The incorporated air content in the fresh state reduced markedly, but did not affect other properties. The mortars with cellulose phosphate, partially replacing the commercial additive showed an improvement of the properties of flexural strength and compressive strength

Efeito da incorporação de diatomita na estabilidade e permeabilidade de compósitos cimentíceos espumados aplicados a poços de petróleo

Lightweight oilwell cement slurries have been recently studied as a mean to improve zonal isolation and sheath-porous formation adherence. Foamed slurries consisting of Portland cement and air-entraining admixtures have become an interesting option for this application. The loss in hydrostatic pressure as a consequence of cement hydration results in the expansion of the air bubbles entrapped in the cement matrix, thus improving the sheath-porous formation contact. Consequently, slurries are able to better retain their water to complete the hydration process. The main objective of the present study was to evaluate the effect of the addition of an air-entraining admixture on the density, stability and permeability of composite slurries containing Portland cement and diatomite as light mineral load. Successful formulations are potential cementing materials for low fracture gradient oilwells. The experimental procedures used for slurry preparation and characterization were based on the American Petroleum Institute and ABNT guidelines Slurries containing a pre-established concentration of the air-entraining admixture and different contents of diatomite were prepared aiming at final densities of 13 to 15 lb/gal. The results revealed that the reduction of 15 to 25% of the density of the slurries did not significantly affect their strength. The addition of both diatomite and the air-entraining admixture increased the viscosity of the slurry providing better air-bubble retention in the volume of the slurry. Stable slurries depicted bottom to top density variation of less than 1.0 lb/gal and length reduction of the stability sample of 5.86 mm. Finally, permeability coefficient values between 0.617 and 0.406 mD were obtained. Therefore, lightweight oilwell cement slurries depicting a satisfactory set of physicochemical and mechanical properties can be formulated using a combination of diatomite and air-entraining admixtures for low fracture gradient oilwells

Compósitos poliméricos a base de fibras de licuri: efeitos da hibridização e do envelhecimento ambiental acelerado

The gradual replacement of conventional materials by the ones called composite materials is becoming a concern about the response of these composites against adverse environmental conditions, such as ultraviolet radiation, high temperature and moist. Also the search for new composite using natural fibers or a blend of it with synthetic fibers as reinforcement has been studied. In this sense, this research begins with a thorough study of microstructural characterization of licuri fiber, as a proposal of alternative reinforcement to polymeric composites. Thus, a study about the development of two composite laminates was done. The first one, involving only the fiber of licuri and the second comprising a hybrid composite based of fiber glass E and the fiber of licuri, in order to know the performance of the fiber when of fiber across the hybridization process. The laminates were made in the form of plates using the tereftálica ortho-polyester resin as matrix. The composite laminate made only by licuri fiber had two reinforcing fabric layers of unidirectional licuri and the hybrid composite had two reinforcing layers of unidirectional licuri fabric and three layers of fiber short glass-E mat. Finally, both laminates was exposed to aging acceleration in order to study the influence of environmental degradation involving the mechanical properties and fracture characteristics thereof. Regarding the mechanical properties of composites, these were determined through uniaxial tensile tests, uniaxial compression and three bending points for both laminates in original state, and uniaxial tensile tests and three bending points after accelerated aging. As regards the study of structural degradation due to aging of the laminates, it was carried out based on microscopic analysis and microstructure, as well as measuring weight loss. The characteristics of the fracture was performed by macroscopic and microscopic (optical and SEM) analysis. In general, the laminated composites based on fiber licuri showed some advantages in their responses to environmental aging. These advantages are observed in the behavior related to stiffness as well as the microstructural degradation and photo-oxidation processes. However, the structural integrity of this laminate was more affected in case the action of uniaxial tensile loads, where it was noted a lower rate of withholding his last resistance property

Desenvolvimento de argamassa para restauração utilizando resíduo do polimento do porcelanato

The coatings mortars are essential elements of building structures because they execute an important role in protecting walls and are particularly exposed to aggressive action responsible for its degradation over time. The importance of wall coverings has been the subject of discussion and analysis in the conservation and rehabilitation of old buildings. Are sometimes removed and replaced with inappropriate solutions of constructive point of view or architecture. The most commonly used coatings on walls of old buildings is based on traditional hydraulic lime mortars. The present study aims at the formulation of new lime- based mortars and aerial fine aggregate, in order to contribute to a better field of conservation and restoration mortar coating of old buildings. Residue was used for polishing porcelain as fine aggregate, replacing the aggregate (sand), in percentages 05-30% by mass. We conducted a thorough evaluation of the mortar properties in fresh and hardened state by comparing the performance of the same with a reference mortar. The residue used was characterized as the density, bulk density, and particle size laser, scanning electron microscopy, X-ray diffraction and X-ray fluorescence. Formulations were produced 7, 6 with residue and one commonly used formulation, which served as a reference. In the formulations of lime mortars air (hydrated lime powder CH-I) has been adopted a stroke volume (1:3) with constant binder, was varied and the water / binder and aggregate and waste. For evaluation of mortars fresh, proceeded to consistency analysis, specific gravity, water retention and air content embedded. In the hardened state assays were performed in specific gravity, water retention, modulus of elasticity, tensile strength in bending, compressive strength, water absorption by capillary action, adhesion, tensile strength, resistance to shrinkage and salts by of crystallization trials with resources chloride solution, nitrate and sulfate all sodium in prismatic at 90 days of age, in addition to the micro structural analysis of mortars. Based on the results we can see that the mortar formulated with 10% content of waste and the reference free retraction feature more stable closer to neutrality. The composition of 10% was obtained better performance against the action of the salt crystallization. The mortar with 15% residue obtained better density, lower air content embedded and high capacity for water retention developing good workability. The replacement of 20% of waste generates a satisfactory utilization of resistance to compression, flexion and traction grip the base. And, finally, it can be seen that the mortar with 10, 15 and 20% residual show, in principle, good suitability as coatings, thus enabling a final result consistent with durability, workability and aesthetics developing therefore a material with better performance to repair or replace existing mortars in old buildings

Estudo da viabilidade do processo de reciclagem do material descartado do sistema Zirkonzanh® de produção de próteses dentárias

At present, the material of choice for performing aesthetic dental prosthetic work is in the ceramic. Among them, the ceramic base of stabilized zirconia with 3% yttria (3Y - TZP) stand out for having excellent physical and mechanical properties. During the machining of blocks of zirconia in the laboratory to prepare the various types of prostheses, much of the material is given off in the form of powder, which is subsequently discarded. The waste of this material results in financial loss, reflecting higher final cost treatment for patients, as well as damage to the environment, thanks to the processes involved in the manufacture and disposal of the ceramic. This research, pioneered the recycling of zirconium oxide powder obtained during milling of dental crowns and bridges, we highlight the social and environmental aspects and aims to establish a protocol for the reuse of waste (powder of zirconia Zirkonzahn® system) discarded to obtain a new block of compacted zirconia to maintain the same mechanical and microstructural properties of commercial high-cost imported material. To compare with the commercial material, samples were uniaxially (20 MPa) and isostatically (100 MPa), and its mechanical and microstructural characterization was performed through tests of density, porosity, dilatometry, X-ray diffraction (XRD), hardness, fracture toughness, resistance to fracture electron microscopy (SEM) and analysis of grain size. The results observed in the samples were isostatically pressed similiares those obtained with samples from the commercial material demonstrating the viability of the process