Diet and food partitioning between juvenile of Epinephelus coioides (Perciformes: Epinephelidae) and other co-existing juvenile fishes in shallow waters of Thailand and Malaysia

This work examined diet composition of the juvenile orange-spotted grouper, Epinephelus coioides, and its trophic association with other juvenile fish species in tropical estuarine habitats during recruitment. From December 2015 to March 2016, juveniles were collected, their stomachs excised, preserved and analyzed. Small shrimps and amphipods, especially Grandidierella sp. and Elasmopus sp., were the most common food resources sharing among the most species. Epinephelus coioides predominantly ingested small shrimp, Grandidierella sp., Elasmopus sp. and fish larvae and had the greatest trophic overlap with Palatrus scapulopunctatus. Fish size, location and month significantly affected fullness indices and food items diversity in E. coioides. It is clear that the larger the size of E. coioides and its mouth opening, the larger the size of items ingested. This study confirms the ontogenetic dietary shift of juvenile E. coioides during recruitment season by starting as amphipod and small shrimp feeder and shifting to shrimp and fish larvae predator as they grow. This finding is fundamental to understanding how juvenile E. coioides cope with different conditions and its association with other co-existing species during the recruitment period

Development of a Chemiresistor Sensor Based on Polymers-Dye Blend for Detection of Ethanol Vapor

The conductive blend of the poly (3,4-ethylene dioxythiophene) and polystyrene sulfonated acid (PEDOT-PSS) polymers were doped with Methyl Red (MR) dye in the acid form and were used as the basis for a chemiresistor sensor for detection of ethanol vapor. This Au | Polymers-dye blend | Au device was manufactured by chemical vapor deposition and spin-coating, the first for deposition of the metal electrodes onto a glass substrate, and the second for preparation of the organic thin film forming ∼1.0 mm2 of active area. The results obtained are the following: (i) electrical resistance dependence with atmospheres containing ethanol vapor carried by nitrogen gas and humidity; (ii) sensitivity at 1.15 for limit detection of 26.25 ppm analyte and an operating temperature of 25 °C; and (iii) the sensing process is quickly reversible and shows very a low power consumption of 20 μW. The thin film morphology of ∼200 nm thickness was analyzed by Atomic Force Microscopy (AFM), where it was observed to have a peculiarly granulometric surface favorable to adsorption. This work indicates that PEDOT-PSS doped with MR dye to compose blend film shows good performance like resistive sensor

Fabrication of Poly(p-Phenylene)/Zeolite Composites and Their Responses Towards Ammonia

Poly(p-phenylene) (PPP) was chemically synthesized via oxidative polymerization using benzene and doped with FeCl3. The electrical conductivity response of the doped PPP (dPPP) towards CO, H2 and NH3 is investigated. dPPP shows no electrical conductivity response towards the first two gases (CO and H2), but it shows a definite negative response towards NH3. The electrical conductivity sensitivity of dPPP increases linearly with increasing NH3 concentration. To improve the sensitivity of the sensor towards NH3, ZSM-5 zeolite is added into the conductive polymer matrix. The electrical sensitivity of the sensor increases with increasing zeolite content up to 30%. The effect of the type of cation in the zeolite pores is investigated: namely, Na+, K+, NH4+ and H+. The electrical conductivity sensitivity of the composites with different cations in the zeolite can be arranged in this order: K+ < no zeolite < Na+ < NH4+ < H+. The variation in electrical sensitivity with cation type can be described in terms of the acid-base interaction, the zeolite pore size and surface area. The PPP/Zeolite composite with H+ possesses the highest electrical sensitivity of −0.36 since H+ has the highest acidity, the highest pore volume and surface area, which combine to induce a more favorable NH3 adsorption and interaction with the conductive polymer

Polypyrrole/graphene composite films synthesized via potentiostatic deposition

A one-step electrochemical process has been employed to synthesize composite films of polypyrrole/graphene (PPy/GR) by electrochemical polymerization on indium tin oxide (ITO) from an aqueous solution containing pyrrole monomer, graphene oxide (GO) nanosheets and sodium p-toluenesulfonate (NapTS). Thermogravimetric analysis (TGA) confirmed the formation of a composite; the degradation temperature of the new hybrid was between those of PPy and GO. Moreover, the bulbous surface of PPy and the almost transparent tissue-like GO nanosheets were replaced by the new appearance of the composite where the surface was flat but creased. As GO is nonconductive, we deduced that it had been reduced to conducting graphene in the composite film during the electrodeposition process, based on an electrical conductivity study measured with a four-point probe. On average, the electrical conductivity of the PPy/GR composites was twofold higher than that of the pure PPy film, indicating that the incorporation of graphene was able to enhance the conductivity of PPy film

Apparent characteristics and taxonomic study of macroalgae in Pattani Bay

2A survey on macroalgae in Pattani Bay was carried out to build up a database resource for the management of algae in the area. From February 2004 to March 2005, samples of macroalgae from 10 sites were randomly collected monthly. Macroalgae were found at 4 sites in the north of the bay, namely Laem Tachi, Lighthouse, Ban Bu Di and Ban Ta Lo Samilae; 3 sites in the east, namely Ban Da To, the Yaring River Mouth and Ban Bang Pu and only one site in the south at Ban Tanyong Lu Lo. Twelve species of 3 divisions of macroalgae were detected. They were Division Cyanophyta, Lyngbya majuscula (Dillwyn) Harvey ex Gomont; Division Chlorophyta; Ulva intestinalis Linnaeus, U. pertusa Kjellman and U. reticulata Forsskal, Rhizoclonium riparium (Roth) Harvey, R. tortuosum Kutzing, Chaetomorpha crassa (C. Agardh) Kutzing and Cladophora sp.; and Division Rhodophyta, namely Gracilaria tenuistipitata Chang et Xia, G. fisheri (Xia et Abbott) Abbott, Zhang et Xia, Hypnea spinella (C. Agardh) Kutzing and Acanthophora spicifera (Vahl) B∅rgesen. Among them, four species were new recordings at Pattani Bay: Lyngbya majuscula, Rhizoclonium riparium, R. tortuosum and Acanthophora spicifera. Most of these seaweeds were found at the east sites in the dry season from February to September 2004 and from January to March 2005. Only a few species could be found in the wet season from November to December 2004

Study of mechanical properties and recommendations for the application of waste Bakelite aggregate concrete

Bakelite waste from industrial manufacturing may be a hazard to the environment and public health. The utilization of waste Bakelite (WB) to replace natural aggregates (NA), such as natural coarse aggregate (NCA) and natural fine aggregate (NFA), in concrete and mortar is an approach for reducing both waste plastic and natural material. This research examines the utilization of waste Bakelite aggregate (WBA) in concrete and mortar mixtures to form waste Bakelite aggregate concrete (WBAC) and waste Bakelite mortar (WBM). The tests cover the physical and chemical properties of WBA, the mechanical properties of WBAC and WBM (including the extraction of chemical substances from WBA utilization to replace NCA and NFA), and recommendations for the application of replacement. The results indicate that WBA particles of different sizes can replace both fine and coarse natural aggregates. Its weight is less than natural aggregate but the absorption rate is higher. As for recommendations for the application, it was found that replacing 20% of NCA with waste Bakelite coarse aggregate in concrete (WBAC-RNCA) was the most suitable proportion, owing to its mechanical properties and safety for the environment and public health, and because its material cost is acceptable. However, the use of waste Bakelite fine aggregate to replace NFA (WBAC-RNFA) in concrete is not appropriate, because its mechanical properties are not sufficient, and it is considered unsafe for the environment and health. Moreover, WBM is not a suitable material for plastering work, since it may be a hazard to the environment and public health, and its cost is higher than conventional mortar. Keywords: Waste Bakelite, Aggregate, Concrete, Morta

Diet and food partitioning between juvenile of

This work examined diet composition of the juvenile orange-spotted grouper, Epinephelus coioides, and its trophic association with other juvenile fish species in tropical estuarine habitats during recruitment. From December 2015 to March 2016, juveniles were collected, their stomachs excised, preserved and analyzed. Small shrimps and amphipods, especially Grandidierella sp. and Elasmopus sp., were the most common food resources sharing among the most species. Epinephelus coioides predominantly ingested small shrimp, Grandidierella sp., Elasmopus sp. and fish larvae and had the greatest trophic overlap with Palatrus scapulopunctatus. Fish size, location and month significantly affected fullness indices and food items diversity in E. coioides. It is clear that the larger the size of E. coioides and its mouth opening, the larger the size of items ingested. This study confirms the ontogenetic dietary shift of juvenile E. coioides during recruitment season by starting as amphipod and small shrimp feeder and shifting to shrimp and fish larvae predator as they grow. This finding is fundamental to understanding how juvenile E. coioides cope with different conditions and its association with other co-existing species during the recruitment period

Mechanical Properties of Parallel TDG Bamboo Laminated Columns with Tough and Grove Joints

The problem of bamboo&rsquo;s strength depends on the length used. From past experiments, it was found that the physical properties of bamboo have thickness at the bottom and a tapered end, resulting in the strength of the bamboo in each part being different. The bottom part can resist more compression than the tip, which corresponds to the physical characteristics of bamboo. To use bamboo for main construction, such as columns, many select raw bamboo that measures approximately 3 m from the ground and is considered the strongest part. The present bamboo laminated products are limited to 2.4 m in length due to the capabilities of today&rsquo;s compression machines and the factor of length as mentioned above. The column is an important infrastructure, which must have sufficient strength and capacity to solve the problem of high space. However, based on the above limitations, it is particularly important to study the connectivity of increasing column length. A wood joint is a traditional method to secure two pieces of wood together. Tongue and groove joints are most common in floorings, such as wood flooring, laminate flooring, and flooring. One of the hardest methods of securing wood is end to end of edge to edge. In order to further develop green building materials, TDG bamboo is processed into laminated columns (TDGLC). It is considered important because, in addition to increasing income for farmers, it will also enable the development of building materials to replace wood in the future. Therefore, this research demonstrates the benefits of developing locally available materials such as bamboo. To develop laminated bamboo columns for use in a structure, we chose 3&ndash;4-year-old TDG bamboo and glued it to obtain a 100 mm cross-section column in order to maximize the benefits of using TDG bamboo for real use. Test specimens are joined by tongue-groove joints to a column length of 1 m, 2 m, and 3 m by joining joints in four different areas: Top (T), middle (M), top-bottom (TB), and bottom (B), to test for compressive strength. The test results showed that TDGLC + TG at the top specimens 4L01 T&ndash;4L03 T can resist a load range of 100&ndash;65%, and for the middle specimen 4L01 M&ndash;4L03 M, the load is between 88 and 57%. At the top-bottom 4L01 TB&ndash;4L03 TB, the load is between 30 and 20%. At the bottom 4L01 B&ndash;4L03 B, the load is between 28 and 18%

Mechanical Properties of Parallel TDG Bamboo Laminated Columns with Tough and Grove Joints

The problem of bamboo’s strength depends on the length used. From past experiments, it was found that the physical properties of bamboo have thickness at the bottom and a tapered end, resulting in the strength of the bamboo in each part being different. The bottom part can resist more compression than the tip, which corresponds to the physical characteristics of bamboo. To use bamboo for main construction, such as columns, many select raw bamboo that measures approximately 3 m from the ground and is considered the strongest part. The present bamboo laminated products are limited to 2.4 m in length due to the capabilities of today’s compression machines and the factor of length as mentioned above. The column is an important infrastructure, which must have sufficient strength and capacity to solve the problem of high space. However, based on the above limitations, it is particularly important to study the connectivity of increasing column length. A wood joint is a traditional method to secure two pieces of wood together. Tongue and groove joints are most common in floorings, such as wood flooring, laminate flooring, and flooring. One of the hardest methods of securing wood is end to end of edge to edge. In order to further develop green building materials, TDG bamboo is processed into laminated columns (TDGLC). It is considered important because, in addition to increasing income for farmers, it will also enable the development of building materials to replace wood in the future. Therefore, this research demonstrates the benefits of developing locally available materials such as bamboo. To develop laminated bamboo columns for use in a structure, we chose 3–4-year-old TDG bamboo and glued it to obtain a 100 mm cross-section column in order to maximize the benefits of using TDG bamboo for real use. Test specimens are joined by tongue-groove joints to a column length of 1 m, 2 m, and 3 m by joining joints in four different areas: Top (T), middle (M), top-bottom (TB), and bottom (B), to test for compressive strength. The test results showed that TDGLC + TG at the top specimens 4L01 T–4L03 T can resist a load range of 100–65%, and for the middle specimen 4L01 M–4L03 M, the load is between 88 and 57%. At the top-bottom 4L01 TB–4L03 TB, the load is between 30 and 20%. At the bottom 4L01 B–4L03 B, the load is between 28 and 18%

Inhibitory Effects of <i>Caulerpa racemosa</i>, <i>Ulva intestinalis</i>, and <i>Lobophora challengeriae</i> on Tyrosinase Activity and α-MSH-Induced Melanogenesis in B16F10 Melanoma Cells

Melanogenesis involves a synthesis of melanin pigment and is regulated by tyrosinase. The addition of whitening agents with tyrosinase-inhibiting properties in cosmetics is becoming increasingly important. In this study, the ethanolic extracts from twelve seaweeds were assessed for tyrosinase-inhibiting activity using mushroom tyrosinase and melanin synthesis in B16F10 melanoma cells. The highest mushroom tyrosinase inhibition (IC50) was observed with Lobophora challengeriae (0.15 ± 0.01 mg mL−1); treatment was more effective than kojic acid (IC50 = 0.35 ± 0.05 mg mL−1), a well-known tyrosinase inhibitor. Three seaweeds, Caulerpa racemosa, Ulva intestinalis, and L. challengeriae, were further investigated for their ability to reduce melanogenesis in B16F10 cells. The ethanolic extracts of C. racemosa, U. intestinalis, and L. challengeriae showed inhibitory effects by reducing melanin and intracellular tyrosinase levels in B16F10 cells treated with α-melanocyte stimulating hormone in a dose-dependent manner. C. racemosa (33.71%) and L. challengeriae (36.14%) at 25 µg mL−1 reduced melanin production comparable to that of kojic acid (36.18%). L. challengeriae showed a stronger inhibition of intracellular tyrosinase (decreased from 165.23% to 46.30%) than kojic acid (to 72.50%). Thus, ethanolic extracts from C. racemosa, U. intestinalis, and L. challengeriae can be good sources of natural tyrosinase inhibitors and therapeutic or cosmetic agents in the future