Utjecaj prirodnog izlaganja vremenskim utjecajima na svojstva kompozita od drvnog brašna i recikliranog polipropilena

In this study, the effect of natural weathering on the physical and mechanical properties of wood plastic composites (WPC) made from virgin and recycled polypropylene (PP) was studied. To prepare the recycled PP, virgin PP was thermo-mechanically degraded by extrusion under controlled conditions in a single-screw extruder at a router speed of 60 rpm and temperature of 190 °C. PP (virgin and recycled), wood flour, compatibilizer, and UV absorbent were physically blended, and the samples were manufactured by a twin-screw extruder. The samples were exposed to natural weathering for 270 days. The surface characteristics of the samples were investigated before and after weathering. According to the results, the composites from recycled PP exhibited a higher weathering resistancethan those from virgin PP. The use of a UV absorber improved the flexural strength and modulus of the composites, but it could not significantly prevent the flexural properties loss and discoloration of the composites after weathering.U ovom je istraživanju proučavan utjecaj prirodnog izlaganja vremenskim utjecajima na fizička i mehanička svojstva drvno-plastičnih kompozita (WPC) izrađenih od čistoga i recikliranog polipropilena (PP). U postupku pripreme recikliranog polipropilena čisti je polipropilen termomehanički razgrađen ekstruzijom s jednim pužem u konstantnim uvjetima i pri brzini vrtnje od 60 okr./min te pri temperaturi od 190 °C. Pomiješani su čisti i reciklirani polipropilen, drvno brašno, kompatibilizator i UV apsorber, a uzorci su proizvedeni ekstruderom s dva puža. Uzorci su bili 270 dana prirodno izloženi vremenskim utjecajima. Svojstva površine uzoraka ispitana su prije i nakon izlaganja tim utjecajima. Iz rezultata je vidljivo da su kompoziti od recikliranog polipropilena pokazali veću otpornost na vremenske utjecaje nego kompoziti od čistog polipropilena. Upotreba UV apsorbera poboljšala je čvrstoću na savijanje i modul elastičnosti kompozita, ali nije značajno spriječila slabljenje svojstava savijanja i promjenu boje kompozita nakon izlaganja vremenskim utjecajima

Exploring the best model for sorting Blood orange using ANFIS method

OranOrange has abundant nutritional properties and is consumed worldwide.  Sorting oranges of different masses based on their physical traits could help reduce packaging and transportation cost.  The ‘Blood’ cultivar of Iranian oranges from Kermanshah province of Iran (7.03 °E 4.22 °N) was used in this study.  100 samples were randomly selected.  During the two-day experiment, all measurements were carried out inside the laboratory at mean temperature of 24°C.  In this study, some physical properties of ‘Blood’ orange were measured, such as length, width, thickness, volume, mass, mean value of geometric diameter, sphericity and projected area.  ANFIS and linear regression models were employed to predict the mass based on sphericity and mean of projected area inputs.  In ANFIS model, samples were divided into two sets, with 70% for training set and 30% for testing set.  The coefficient of determination (R2) for ANFIS and linear regression models were 0.983 and 0.927, respectively.  It is shown that the mass can be estimated based on ANFIS model better than linear regression model.   Keywords: linear regression, orange, packaging, physical properties, sorting

Mating system in the shrimp Arete indicus, a symbiont of Echinometra mathaei

248-252Due to their solitary life style, it appears that Arete indicus have a ‘search and attend’ mating system. There was a correlation between the body size (carapace length) of males and females found in pairs. There was a tight correlation between the numbers of total spine of their host and the number of individuals inhabiting the urchin. There was a weak and non-significant relationship between the number of males and females present and the volume of their host

Sexual system and Sexual dimorphism in the shrimp Arete indicus, symbiont with the sea urchin Echinometra mathaei in the Persian Gulf, Iran

259-262The sexual system and sexual dimorphism of the shrimp Arete indicus are described. The following were measured for all shrimp under stereomicroscope to the nearest ±0.01 mm: carapace length (CL), merus length (ML) and carpus length (CrL) of the largest of the first pair of chelipeds, pleural width of the second abdominal segment (PW), and propodus length (PL) of the second (larger) pair of chelipeds. Sex determinations were based on presence of the appendix masculina on the base of the endopod of the second pleopods. With a view to determine whether or not a linear relationship exists between the CL, PL, ML, CrL and PW, the allometric model y = axb was used. A correlation was found between CL and ML in both sexes of Arete indicus. The status of allometry differed among various body parts of both sexes, and degree of allometry differed among various body parts between the sexes. According to ANCOVA, PW, PL, and ML of females are not larger than that of males at any given body size .The CL of Arete indicus females was not larger than the males. Due to observation a few of males with tiny appendices masculina, also based on earlier literature worked on Arete indicus, we believe this species is partially protandric

Modeling of wheat yield and sensitivity analysis based on energy inputs for three years in Abyek town, Ghazvin, Iran

To get a proper energy consumption pattern and an increase in energy productivity, determining a relationship between energy inputs and outputs is necessary.  In this study, the equivalent energy of inputs and outputs data used in wheat production in Abyek town of Ghazvin province, Iran was collected from farmers over three years.  The energy ratio was obtained as 2.11, 2.08 and 2.03 and energy productivity was obtained as 0.15, 0.14 and 0.14 (kg MJ-1) for 2010, 2009 and 2008, respectively.  It was found that the contributions of indirect and non-renewable energies on wheat yield were more than the impacts of direct and renewable energies.  To determine the effects of energy inputs on wheat yield, the Cobb–Douglas production function was used.  Model 1 was composed of individual energy inputs: labor, machinery, electricity, diesel fuel, water for irrigation, fertilizer, chemicals and seed energies  In Model 2 energy inputs divided to direct and indirect energies and in Model 3 they divided to renewable and non-renewable energies.  The R2 values in all three models were more than 0.98 and showed that the models can estimate well.  The sensitivity analysis results for Model I showed that the major marginal physical productivities (MPPs) were water for irrigation, human labor and water for irrigation in 2010, 2009 and 2008, respectively. In Model II, the major MPP belongs to for renewable energy in the same years.   Keywords: energy consumption pattern, Cobb-Dauglas, marginal physical productivity, renewable, return to scal

In Vitro Study of Mebendazole (Anthelmintic drug) Effects on the Aspartate Aminotransferase (AST) Enzyme Activity of Hydatid Cyst Parasite

Hydatid disease is caused by the larva of Echinococcus granulosus parasite. Mebendazole (MBZ) is used as an alternative choice for the treatment of the disease. Aspartate aminotransferase (AST) is an essential enzyme in amino acid metabolism. The aim of the present study is to evaluate the effect of MBZ on AST activity of hydatid cyst parasite in order to detect enzymatic parameter for drug efficiency. In the present study, AST activity was estimated in the extracts of untreated parasite (hydatid cyst protoscolices) and treated samples by MBZ (100 µg final concentration). Samples’ protein quantity and quality were detected by Bradford and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) methods respectively. For the purpose of determining the significant difference between the two independent samples, t-test was conducted. The values of the assayed AST specific activities of treated and untreated parasite samples were measured as 0.18 and 1.53U/ml/mg protein respectively. The difference between AST activities mean values of the two groups proved to be significant (P<0.05). SDS-PAGE demonstrated protein band of 50 kDa for AST enzyme. Considering the effect of the MBZ drug on AST activity in parasite, it can be concluded that this enzyme is useful for improving the drug efficiency

Species Composition and Functiona Traits of Macrofauna in Different Mangrove Habitats in the Persian Gulf

Macrofauna play a key role in the functioning of mangrove ecosystems. Nevertheless, our understanding of the diversity and functional structure of macrofaunal communities across different habitats in the mangrove forests of the Persian Gulf is limited. In this study, we investigated species diversity and biological trait patterns of macrofauna in different mangrove-associated habitats, i.e., encompassing actual mangrove forests, and adjacent Beaches and Creeks, which exhibit different levels of habitat heterogeneity. Samples were collected from the different habitats in five different locations, over four seasons. A total of 122 macrofauna taxa were identified. The diversity of species was higher in summer than in winter. In the Beach habitats, species diversity showed an increasing trend from land toward the mangrove, whereas in Creek habitats diversity decreased from the Creek toward the mangrove. Multivariate community analysis showed differences in the distribution of abundant species and biological traits across all habitats. Deposit-feeding, crawlers, medium-size, and free-living were the dominant trait modalities in all habitats. The similarities within habitats over the four seasons had the same specific pattern of species and biological trait abundance in the Beach and the Creek, increasing from the non-covered habitat into the mangrove trees. Although many species shared similar traits, the abundance-driven differences in trait expression between habitats showed the importance of habitat filtering. The results of this study will be useful in the conservation of mangrove forests and they give a deeper understanding of the ecological patterns and functions of benthic macrofaunal communities in the Persian Gulf.Peer reviewe

Faunistic study on hover flies (Diptera:Syrphidae) in the eastern part of Zanjan province, Iran

Abstract In order to study on Syrphidae faunistic in the eastern part of Zanjan province in the years of 2008 and 2009, some adult specimens were collected and identified. In total, 31 species belong to 16 genus from 2 subfamilies were collected. Among the specimens, 28 species as follow are new records for Zanjan province and the species marked with an asterisk is the first record from Iran

Grain Boundary Phases in NbFeSb Half-Heusler Alloys: A New Avenue to Tune Transport Properties of Thermoelectric Materials

Many thermoelectric materials benefit from complex microstructures. Grain boundaries (GBs) in nanocrystalline thermoelectrics cause desirable reduction in the thermal conductivity by scattering phonons, but often lead to unwanted loss in the electrical conductivity by scattering charge carriers. Therefore, modifying GBs to suppress their electrical resistivity plays a pivotal role in the enhancement of thermoelectric performance, zT. In this work, different characteristics of GB phases in Ti-doped NbFeSb half-Heusler compounds are revealed using a combination of scanning transmission electron microscopy and atom probe tomography. The GB phases adopt a hexagonal close-packed lattice, which is structurally distinct from the half-Heusler grains. Enrichment of Fe is found at GBs in Nb0.95Ti0.05FeSb, but accumulation of Ti dopants at GBs in Nb0.80Ti0.20FeSb, correlating to the bad and good electrical conductivity of the respective GBs. Such resistive to conductive GB phase transition opens up new design space to decouple the intertwined electronic and phononic transport in thermoelectric materials