81 research outputs found
The environmental noise level in the rejuvenation pruning on centuries-old olive tree
ArticleIn the Italian agricultural economy, olive cultivation plays a fundamental role, and this
is especially true for the southern regions where almost all cultivation is spread. In Calabria, in
particular, olive cultivation has seen over the last few decades significantly improve the quality
of production also as a result of investments aimed at the creation of new mechanizable plants
and/or the modernization of existing ones; today some areas have got both PDO and PGI
certification.
In the ‘Piana di Gioia Tauro’, located north-west of the Reggio Calabria metropolitan area, olive
growing extends over 20,000 hectares and the presence of centuries-old olive tree is still
widespread. The olive varieties mainly belong to the local cultivars of ‘Sinopolese’ and
‘Ottobratica’, characterized by a remarkable rusticity and high development, perhaps unique in
the world; they reach 20–25 meters high, forming what is called a ‘forest of olive trees’.
The pruning operations are carried out by means of chainsaws of different power and size
whereby, in addition to the previously described difficulties, operators are exposed to prolonged
periods of noise levels. The purpose of this study is precisely to assess the exposure of operators
to this particular olive grove. The aim is to identify the acoustic levels generated by the two
pruning and cross-cutting activities, the risk thresholds and the exposure to which the individual
workers of the two work sites are subjected, giving indications on the appropriate safety distances
to maintain (according to current regulations) compared to noise sources
Electricity from Wood: A Wood Quality and Energy Efficiency Approach to Small Scale Pyro-gasification
AbstractThe global demand for renewable energy in the last years is facing innovations like the co-generation of electricity and heat from wooden industrial residues and biomass. Wood gasification is a very promising technique for conversion of wood chemical energy into thermal energy and into electricity. A new generation of small scale, moderately priced and easy to install pyro-gasification plants became available on the market, being an opportunity for the SMEs. These systems are also characterized by a remarkable operational easiness and great versatility in the type of used biomass, which can range from industrial residues (sawdust, wood chips...) to biomass of forestry and non-forestry origin. This study performed an extensive testing of a small size pyro-gasification plant capable of producing 30kW of electricity and 30kW of thermal energy, both net to enter in the network of GSE (Energy Services Manager) via the feed-in tariff and in a small district heating network or other uses. The process of pyro-gasification is analyzed in its entirety by a characterization of input biomass, pyro-gasification process monitoring, analysis of the quality of the produced syngas, characterization of residues due to the process (washing water smoke, charcoal...) and verification of the total efficiency. The electric efficiency of the system, from hardwood to syngas to electricity is quantified in being 12%
The assessment of hazelnut mechanical harvesting productivity
ArticleHazelnut cultivation represents a new opportunity for Calabrian mountainous and
sloping areas (Southern Italy), where no alternative fruit crops, except forestry, could be settled.
In this Region, hazelnut production doubled during the last fifty years, inciting the farmers to
introduce mechanization in cropping practices such as harvesting in order to increase productivity
and decrease production costs. Indeed, harvesting is currently one of the most expensive
processes of the productive cycle, moreover to be time consuming if carried out manually.
Mechanization degree depends significantly on the terrain topography: in sloping areas, rakes are
often associated to aspirating machines to harvest the fallen fruit, while the employment of
harvesting machines from the ground prevails in flat areas. In this context, the present paper aims
to assess technical and economic aspects of harvesting operation, using a harvester from the
ground model ‘Jolly 2800’ (GF s.r.l., Italy). Particularly, for technical purposes data about
operational working time as well as working productivity were collected according to CIOSTA
requirements, in two harvesting sites, whereas, for mechanical harvesting economic evaluation,
an estimation model was applied to calculate machinery cost per hour. Moreover, the cost per kg
of hazelnut in shell and the average cost per hectare were estimated also. The obtained results
show a working productivity of 0.065 ha h-1 op-1
in the first harvesting site, while it was equal to
0.022 ha h
-1 op-1
in the second one. Concerning the average cost per hectare, the second
harvesting site showed the worst economic performances, with 550.76 € ha-1
against
182.54 € ha-1 obtained in the first one
Avaliação do efeito do eucaliptol nas convulsões induzidas por pentilenotetrazol em camundongos
The developmental process of epilepsies involves diverse mechanisms that culminate in the hyperactivity of a population of neurons, resulting in a pattern of repeated and rhythmic depolarizations. Antiepileptic drugs act by increasing GABAergic neurotransmission, reducing the effects of glutamate, or blocking ion channels, and are endowed with serious adverse effects that make it difficult for patients to adhere to treatment. This fact has encouraged the search for compounds of natural origin with potential anticonvulsant effect. Thus, the present study aimed to evaluate the effect of eucalyptol in seizures induced by pentylenetetrazole (PTZ). For this, male Swiss mice, orally treated with monotrepene, were used. The first protocol evaluated the toxicity and the estimated LD50 of the compound. Based on the value of LD50, the doses of terpene used in the behavioral and neurochemical tests were selected. For the behavioral tests, groups of mice were pretreated with saline (10 mL/kg, vol), diazepam (2 mg/kg, ip) and eucalyptol (100, 200 and 400 mg/kg, vol) and then with pentylenetetrazole 80 mg/kg, ip) and evaluated for the following parameters: seizure intensity, latency for first seizure and time of death. For neurochemical tests, groups of mice were pretreated with saline (10 mL/kg, v.o.) and eucalyptol (400 mg/kg, i.p.) and subsequently with pentylenetetrazole (80 mg/kg, i.p.); The determination of the concentration of neurotransmitters (monoamines - dopamine, noradrenaline and serotonin) and oxidative stress markers (nitrite and thiobarbituric acid reactive substances - TBARs) were the parameters evaluated. The results were analyzed by ANOVA or Kruskal-Wallis, followed by Student-Newman-Keuls, and Dunns, respectively. Values of p <0.05 were considered significant. The results showed that oral administration of eucalyptol had low toxicity and the estimated LD50 was greater than 2000 mg / kg. In the PTZ-induced seizure test, only the higher dose of monoterpene (400 mg/kg) significantly reduced seizure intensity by 60%, increased latency for onset of the first seizure by 85% and time of death of the animals in 75% in relation to the control. Similarly, treatment with eucalyptol (400 mg/kg) significantly reduced the concentration of noradrenaline, dopamine and serotonin by 50%, 33% and 70%, respectively, in relation to the PTZ-treated group (80 mg/kg). In addition, treatment with eucalyptol (400 mg/kg) significantly reduced the concentration of TBARs by 33%, but not nitrite, relative to the PTZ treated group (80 mg/kg). Taken together, the results show that the monoterpene studied has low oral toxicity and an important anticonvulsant effect, since its administration is capable of attenuating the convulsions chemically induced by pentylenetetrazol with consequent reduction of the concentration of monoamines and the reactive substances of thiobarbituric acid, elements whose increase is associated with the epileptogenesis phenomenon.O processo de desenvolvimento das epilepsias envolve mecanismos diversos que culminam na hiperatividade de uma população de neurônios, resultando em um padrão de despolarizações repetidas e rítmicas. Os fármacos antiepilépticos agem através do aumento da neurotransmissão GABAérgica, da redução dos efeitos do glutamato, ou do bloqueio de canais iônicos, sendo dotados de efeitos adversos sérios que dificultam a adesão do paciente ao tratamento. Este fato tem incentivado a busca por compostos de origem natural com potencial efeito anticonvulsivante. Desta forma, o presente trabalho teve como objetivo avaliar o efeito do eucaliptol nas convulsões induzidas por pentilenotetrazol (PTZ). Para tanto, foram utilizados camundongos Swiss machos, tratados oralmente com o monotrepeno. O primeiro protocolo realizado avaliou a toxicidade e a DL50 estimada do composto. Com base no valor da DL50, foram selecionadas as doses do terpeno utilizadas nos testes comportamentais e neuroqímicos. Para os testes comportamentais, grupos de camundongos foram previamente tratados com salina (10 mL/kg, v.o.), diazepam (2 mg/kg, i.p.) e eucaliptol (100, 200 e 400 mg/kg, v.o.) e posteriormente com pentilenotetrazol (80 mg/kg, i.p.) e avaliados quanto aos seguintes parâmetros: intensidade das convulsões, latência para primeira convulsão e tempo de morte. Para os testes neuroquímicos, grupos de camundongos foram previamente tratados com salina (10 mL/kg, v.o.) e eucaliptol (400 mg/kg, i.p.) e posteriormente com pentilenotetrazol (80 mg/kg, i.p.); a determinação da concentração de neurotransmissores (monoaminas – dopamina, noradrenalina e serotonina) e dos marcadores de estresse oxidativo (nitrito e substâncias reativas do ácido tiobarbitúrico – TBARs) foram os parâmetros avaliados. Os resultados foram analisados por ANOVA ou Kruskal-Wallis, seguido dos testes de Student-Newman-Keuls, e Dunns, respectivamente. Foram considerados significativos os valores de p < 0,05. Os resultados mostraram que a administração oral do eucaliptol apresentou baixa toxicidade e a DL50 estimada foi superior a 2000 mg/kg. No teste das convulsões induzidas por PTZ apenas a dose maior do monoterpeno (400 mg/kg) reduziu de forma significativa a intensidade das convulsões em 60%, aumentou a latência para aparecimento da primeira convulsão em 85% e o tempo de morte dos animais em 75% em relação ao controle. De forma semelhante, o tratamento com eucaliptol (400 mg/kg) reduziu de forma significativa a concentração de noradrenalina, dopamina e serotonina, em 50%, 33% e 70%, respectivamente, em relação ao grupo tratado com PTZ (80 mg/kg). Além disso, o tratamento com eucaliptol (400 mg/kg) reduziu de forma significativa a concentração de TBARs em 33%, mas não de nitrito, em relação ao grupo tratado com PTZ (80 mg/kg). Tomados em conjunto, os resultados mostram que o monoterpeno estudado apresenta baixa toxicidade oral e importante efeito anticonvulsivante, visto que sua administração é capaz de atenuar as convulsões quimicamente induzidas por pentilenotetrazol com consequente redução da concentração de monoaminas e das substâncias reativas do ácido tiobarbitúrico, elementos cujo aumento está associado ao fenômeno da epileptogênese
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