Annually, thousands of tons of rubber tires are produced, consumed, and discarded within the country. In recent decades, researchers have investigated the use of rubber fibers or rubber crumbs in concrete and their effects on its mechanical properties. However, the simultaneous utilization of both these materials as substitutes for sand and gravel in concrete has not been thoroughly explored. In this research, this research gap is addressed by examining the results of slump tests on rubber concrete specimens with water-to-cement ratios of 0.45, 0.50, and 0.55, incorporating rubber crumb and rubber fibers up to 25%. The test results indicate a reduction in compressive strength with increasing rubber content. By using different water-to-cement ratios, various rubber concrete proportions, and the SIMAPro software, it was determined that the combination of rubber crumb and rubber fibers leads to approximately a 40% reduction in carbon dioxide emissions in the environment. The optimal condition for all ratios is achieved by adding 4% rubber crumb and rubber fibers.

In this study (Winter, 2007), the changes of histamine content as chemical parameter of spoilage was monitored in the muscle tissue of whole croaker (Otolithes rubber) during ice storage for a period of 18 days (0, 3, 6, 9, 12, 15 and 18th day). Histamine was not detected in the first and 3rd storage days. The first detection of histamine was in the 6th storage day. Initial concentration of histamine was 1.49mg/g and finally reached 14.21 mg/g. Results showed that the concentration of histamine increased linearly (P<0.05) during ice storage (Except day 15). According to the results of this research, the mean concentration of histamine (mg/g) was found less than permissible limits of international standards.

Scrap rubbers can be reclaimed, processed and crosslinked. But, because of the wide use of synthetic rubbers in making many products and the absence of scrap rubbers, reclaim rubbers do not play an important role in rubber industry. They are however used in specific applications. Therefore, it should be mentioned that the main motivation behind this study has been to make a survey on its economic feasibility, application fields and finally, to tackle the problem of environmental pollution. In this paper, reclaimed rubber substitution for NR, SBR and BR with carbon black in cars' light weight tire manufacturing has been studied, and the optimum and favoured properties for static use items have been reached.

Bitumen in pure form is not suitable for modern roads and present traffic. This has forced engineers to modify bitumen to improve its performance during service life. Two routes are known for bitumen modification, that is chemical and physical modifications. Therefore, there are chemical and physical modifiers. Among physical modifiers, polymers (thermoplastics, rubbers and thermosets) are the most interesting ones. Rubbers are very good bitumen modifiers. In this work non-vulcanized rubbers were incorporated into bitumen. The resulting blends showed better high and intermediate performance compared to the base bitumen. The improved properties are lower penetration and higher softening point. The low temperature properties such as Frass breaking point were not improved. New formulae for estimating bitumen’s performance using the results of conventional Frass and ring and ball tests were introduced. The morphology of the blends, depending on the rheological properties and compatibility of the rubber with bitumen, was different. Polybutadiene formed a continuous phase mixture in bitumen. This was observed due to the compatibility of this rubber with bitumen. Due to lesser compatibility between polymer and bitumen, SBRs and natural rubber formed polymeric inclusion dispersed in bitumen.

In order to evaluate the feeding habits of tiger-toothed croaker (Otolithes rubber) 239 specimens were collected during December to March, 2003 in coastal areas of Chabahar, Iran. Stomach contents were examined by using of the numerical method. The abundance and frequency percents and type of preys, along with the percentage of emptiness of stomach, and prey dominant were evaluated during different months and in different groups based on upon length, sex and maturity. Result showed that in tiger-toothed croaker prey fish was the dominant and specific food item. There were monthly changes in feeding intensity and the feeding was weak. The percentage of emptiness stomach in March and December were highest and lowest, respectively. The empty stomach index (CV) indicated that tiger toothed croaker belong to the fish group with medium food intake. Shrimp was the main food in immature fish and with increasing in length and maturity of fish; shrimps were replaced with fish prey as the main food.

In this study, the digestive systems of 10 adult Otolithes ruber specimens from Bushehr I province water, south-west Iran were removed and the livers and pancreases were fixed in formalin 10%. The routine procedures of preparation of tissues were followed and the paraffin blocks were cut at 6 microns, stained with H&E and studied under light microscope. The results of microscopic studies showed that liver as the largest accessory organ surrounds the pancreatic tissue in the fish. Liver was found to be a lobulated organ encircling the pancreas among its lobules. Hepatic tissue of the fish was found to be similar to many other bony fishes. Hepatocytes included glycogen and fat vacuoles that located around the hepatic sinusoids. Pancreas as a mixed gland microscopically, was composed of lobules consisting of serous acini (exocrine portion) and langerhans islets (endocrine portion). Pancreatic lobules are usually found as two rows of acini which a large blood vessel located in between.

In this research the effect of four different coupling agents, widely used in rubber industry, on mechanical properties of natural rubber/reclaim rubber blend is investigated. Used coupling agents are triallyl ciyanurate (TAC), bis (3-triethyloxysiloylpropyl) tetrasulfide (Silane Si69), m-phenylenedimaleimide (HVA-2), and Rhenofit 1986, a combination of activating substances based on urea and surface-active agent. The results show that HVA-2 and Rhenofit do not improve mechanical properties of natural rubber/reclaim rubber blend. Silane (Si69) increases tensile strength and hardness while it does not enhance elastic based properties such as resilience, fatigue life and compression set resistance. While TAC coupling agent increases the tensile strength but has no significant effects on modulus and elongation- at-break.

Effect of the blends of different polyethylenes (LDPE=low-density polyethylene, LLDPE=linear low density polyethylene and HDPE=high density polyethylene) and rubbers (PBR= polybutadine rubber, SBR=styrene butadiene random copolymer, NR=natural rubber and SEBS=styrene-ethylene-butylene-styrene block copolymer) on bitumen properties was investigated. PBR-PE blends form a physical network in bitumen medium, whereas their SBR, NR and SEBS counterparts do not. The properties of the resulting bituminous blends are comparable with those of SEBS blends. LLDPE shows a higher rate of effectiveness on bitumen properties as compared with other polyethylenes. SBR blends show a better elastic recovery and film forming properties. Addition of heavy vacuum slops (HVS) oil into the ternary blends of rubber-PE-Bitumen results in rubber inclusions volumes. The rubber swelling increases as HVS oil concentration increases. HVS oil concentration could be adjusted depending on the designed performance grade (PG). SBR-PE blends found to be the most effective blends on bitumen properties.