Development of Polymer Nanocomposites for Rapid Manufacturing Application

This paper presents initial development of polymer nanocomposites (PNC) material for rapid manufacturing (RM) application. PNC materials containing a polyamide (PA) and nano particles (5wt%) were produced by solution blending with the aim to improve the mechanical properties. Commercial polyamide 6 (PA6) was dissolved in formic acid (HCO2H) together with two different types of nano particle materials: yttrium stabilised zirconia (YSZ) and Hectorite clay (Benton 166) and spray-dried to create powder, creating powder with particle sizes in the range of 10-40 μm. The materials were processed on a CO2 selective laser sintering (SLS) experimental machine. Mechanical properties of the PNCs were evaluated and the results were compared with the unfilled base polymer. Good dispersion of additives was achieved by solution blending, however the PA6 was degraded during the material preparation and spray drying process which resulted in the formation of porous structure and low strength. However the addition of 5 (wt%) nano particles in the PA6 has shown to increase strength by an average of 50-60%. Further work on powder preparation is required in order to fully realise these performance benefit

Effects of iso-nitrogenous fertilizers as nutrient sources on carp polyculture in Bangladesh

A 120-day long experiment was conducted to find out the effects of urea plus triple super phosphate (UT), cow manure (CM) and poultry manure (PM) having iso-nil:rogen content on pond productivity and fish yield. Three fertilizer treatments, with three replicates each, were randomly assigned into nine earthen ponds of 100 m2 each. The stocking fish were rohu (Labeo ruhita), catla ( Catla catla) and mrigal ( Cirrhinus mrigala) in each treatment pond at the rate of 10000/ha with the ratio of 1:1:1. All ponds were fertilized fortnightly at the rate of 125 kg/ha urea plus 100 kg TSP/ha, 7000 kg/ha cow manure and 3500 kg/ha poultry manure for the treatment of UT, CM and PM, respectively, having an iso-nitrogen content of 56 kg in each. Though the physicochemical water quality parameters were more or less similar in all treatment ponds, the chlorophyll-a content and abundance of total plankton were significantly higher (P < 0.05) in the ponds receiving the treatment PM. Final growth as well as per unit production of fish was significantly higher (p<O.OS) with the treatment of PM (2067 kg/ha/4 months) followed by UT (1639 kg/ha/4 months) and CM (1246 kg/ha/4 months). The overall results showed that the poultry manure proved to be superior to urea plus TSP and cow manure, even when nitrogen content is similar, in carp polyculture system under prevailing conditions

Effects of iso-nitrogenous and iso-phosphorus fertilizers as nutrient sources on carp polyculture in Bangladesh

A 120 day long experiment was conducted to find out the effects of cow manure with urea and triple super phosphate (CUT), poultry manure with urea and triple super phosphate (PUT) and cow manure with poultry manure (CP) having similar quantities of nitrogen and phosphorus on pond productivity and fish yield. The stocking fish were rohu (Labeo rohita), catla ( Catla catla) and mrigal ( Cirrhinus mrigala) in each treatment pond at the rate of 10000/ha. All ponds were fertilized fortnightly at the rate of 4000 kg/ha cow manure with 62 kg/ha urea and 65 kg/ha TSP, 2700 kg/ha poultry manure with 62 kg/ha urea and 16 kg/ha TSP, and 4000kg/ha cow manure with 2700 kg/ha poultry manure for the treatment CUT, PUT and CP respectively. Each treatment contained an iso-nitrogen and iso-phosphorus of 56 kg and 46 kg respectively. Though the physico-chemical parameters were more or less similar in all ponds, the chlorophyll-a content and abundance of total plankton were significantly higher (P< 0.05) in the ponds receiving the fertilizer treatment of PUT than those of other treatments. Final growth as well as per unit production of fish of treatment PUT (1773 kg/ha) was significantly higher (P< 0.05) than that of treatment CP (1528 kg/ha) followed by that of treatment CUT (1336 kg/ha). The over all results showed that poultry manure with urea and triple super phosphate proved to be superior to cow manure with urea and triple super phosphate, and poultry manure with cow manure, even when nitrogen and phosphorus content was similar, in carp polyculture system under prevailing conditions

Water quality parameters of coastal shrimp farms from southwest and southeast regions of Bangladesh

The impacts of shrimp farming on water quality and effluent loading of shrimp farms in southwest (Khulna) and southeast (Cox's Bazar) regions of Bangladesh was investigated during March-August and August-October season, respectively. Water salinity fluctuated from 3.0 to 15.0 ppt in the southwest, whereas it was between 2.5 to 20.0 ppt. in southeast region. Total ammonia nitrogen as recorded in most farms of Cox's Bazar region was higher (0. 1160.438 mg/L) than the recommended level of shrimp farming. Mean values of total ammonia nitrogen and total nitrogen at the outlet of shrimp farms were higher than those of inlet in both regions. Mean values of phosphate phosphorus and total phosphorus at outlet were lower than inlet except in harvest time of Penaeus monodon. Total suspended solids were deposited on the bottom of shrimp farms in both regions, which resulted in higher concentration in inlets than outlets in both regions

Impacts of Thai silver barb (Puntius gonionotus Bleeker) inclusion in the polyculture of carps

The impact of inclusion of Thai silver barb, Puntius gonionotus (Bleeker) in the polyculture with two major Indian carps viz., Labeo rohita, Catla catla and common carp Cyprinus carpio has been studied in seasonal ponds for 115 days. The presence of silver barb decreased the growth of Indian carps while increased that of common carp. A significantly higher (P<0.05) fish yield (1793.65 Kg/ha/yr) was observed in the four species polyculture system containing silver barb when the combined yield of all species was compared

Diversity and distribution of medicinal plants in North Sinai, Egypt

The present study aims to assess plant diversity and distribution of medicinal plants in relation to environmental factors at three geomorphological districts (Mediterranean coast, anticlines, and inland) and five main habitats (salt marshes, sand dunes, sand plains, wadis, and gorges) in North Sinai. The results revealed that North Sinai harbors 281 species with high taxonomic diversity (species/genera = 1.49) and high percentage of rare and very rare species (67%). Mediterranean coastal district and anticlines district are more diverse than inland district. Medicinal plants constitute 43% of North Sinai flora. Species richness, Shannon-Weiner H, and Margalef indices measurements indicated that gorges are the most diverse habitat in North Sinai followed by wadis. Plains have intermediate diversity followed by sand dunes. The lowest diversity indices were recorded at salt marshes habitat. Beta diversity measurements, using Wilson and Schmida index (βT), indicated significant changes in floristic compositions between different habitats. The lowest changes were among sand plain, wadi, and gorge habitats. North Sinai habitats support about 100 to 120 medicinal plant associations. The main dominant species include Artemisia monosperma, Arthrocnemum macrostachyum, Lycium shawii, Retama raetam, Stipagrostis scoparia, Tamarix nilotica, Zygophyllum album, and Zygophyllum dumosum. Soil physical properties in addition to soil salinity and topographic variations are the main driving factors controlling the distribution of medicinal plants in North Sinai. About 60% of medicinal plants are threatened due to intensive collection and other human activities. The threatened medicinal plants including Acacia pachyceras, Acacia tortilis, Anastatica hierochuntica, Asclepias sinaica, Capparis spinosa, Chiliadenus montanus, Citrulus colocynthis, Ephedra alata, and Juniperus phoenicea along with their habitats should have the first priority in management and conservation plan of medicinal plants in North Sinai. Public and private involvement in management and utilization of medicinal plants in sustainable way is essential to combat human pressures on these valuable natural resources.Key words: Conservation, diversity, habitats, human impacts, medicinal plants, vegetation

Development of PEBAX Based Membrane for Gas Separation: A Review

Polymer is among the favorite materials used for membrane separation as they are cheap, easily cast, low maintenance cost and commercially easy to get eventhough the material needs to be altered to meet the separation industry specific needs. There are two common issues in membrane preparation which are the produced sheet are too brittle and has no strength to withstand pressure during separation process and the porosity of the sheet sometimes not suitable with the gas kinetic diameter for the separation to occur. PEBAX or Poly ether block amide is the answer for the issues as this elastomer provides good mechanical strength from the hard segment of the crystalline poly amide block while the soft polyether will drive the separation process. This unique material can be casted either by phase inversion of the PEBAX itself with other polymer or by coating them on the other polymer substrate

Higher critical current density achieved in Bi-2223 High-Tc superconductors

AbstractBi2Sr2Ca2Cu3Ox (Bi-2223) were prepared using a solid state reaction method at different sintering times and temperatures. Structural phase identifications have been done using X-Ray analysis and refinement by Reitveld method which proves the coexistence of Bi-2223 and Bi-2212 phases. The critical transition temperature Tc and critical current density Jc values were measured using superconducting quantum interference device magnetometer (SQUID) and by the magneto-optics technique. A remarkable rapid decrease to the diamagnetic signal in the magnetization versus temperature M(T) at 110 K and Jc around 1.2 × 107 A/m2 at 5 K are confirmed for the Bi-2223 compound

Rapid Prototyping of Wood-Based Material

This paper presents initial development of wood-based composites with the aim to develop an alternative material at low cost for rapid prototyping process. Powder blends containing wood powder (90-120μm) with commercial ZP102 as a plaster powder material from ZCorporation were mechanically blended to produce different composition of (vol.%) 25:70, 50:50 and 75:25 respectively. The blended material were successfully processed on 3D printers (Z406) which was used as a rapid prototyping machine to produce three-dimensional components and followed by posttreatment with ZMax solution to improve the mechanical properties. The mechanical properties, dimensional accuracy and surface quality of the build components were evaluated and the results were compared with the unfilled ZP102 material. The result shows that the mechanical properties were improved with the increasing of wood powder content up to 50 vol.%. However, dimensional accuracy and surface quality were decreased as the wood content increased. Further work on powder preparation is required in order to fully realize these performance benefits particularly for surface quality improvement

Quality assessment of traditional and solar tunnel dried SIS (Small Indigenous Fish Species) products

Studies were conducted to assessment the quality of traditional and solar tunnel dried SIS products. The moisture content of the solar products ranged from 14.38 to 18.48% with the lowest in batashi and the highest value in tengra. The moisture content of the traditional products was in the range of 23.26 to 26.42%. The range of protein contents on moisture free basis was from 67.57 to 71.90% in solar dried fishes with highest value obtained in dhela and lowest value in batashi. These values were more or less similar to those of traditional dried SIS products which were in the range of 68.02 to 73.54% on dry weight basis. Lipid contents of solar dried SIS varied from 14.10 to 16.26% and on moisture free basis the in the range of 11.73 to 21.98 with highest value found in tengra and lowest in puti. These values were more or less similar to those found for traditional dried products on dry weight basis and ranged from were 12.37 to 22.43%. Maximum reconstitution of solar dried products was obtained at 80°C in all samples and was in the range of 65.26 to 70.51% where the percentage of reconstitution increases with the increase of socking time and reach maximum at the end of up to 60 min. The TVB-N content of solar dried fish is low compared with traditional one ranging from 20.30 to 28.40mg/100g and peroxide value in the range of 12. 54 to 19.20meq./kg oil. The TVB-N of traditionally dried products were in the range of 32.50 to 45.45mg/100g and PO values of the traditionally dried products were in the range of 30.00 to 36.00meq./kg oil. The bacterial load of the solar dried products was in the range of 4.0x10 super(3)/g to 3.6x10 super(5)CFU/g and of the traditionally dried products ranged from 1.45x10 super(5) to 2.52x10 super(6) CFU/g