Background: In megavoltage radiotherapy rooms, ordinary concrete is usually used due to its low construction costs, although higher density concrete are sometimes used, as well. The use of high-density concrete decreases the required thickness of the concrete barrier hence, its disadvantage is its high cost. In a nuclear reactor, neutron radiation is the most difficult to shield. A method for p...

the nanostructured anatase tio2 with high thermal stability was prepared by polymeric sol-gel method without any additives. the particle size distribution of polymeric titania sol was determined by dynamic light scattering (dls). then properties of obtained titania were investigated by tg-dta, xrd, fesem and tem. also, the decolorization capability of resultant anatase was evaluated using methy...

regarding the increasing demand for lightweight concrete especially lightweight structural concrete, and safety requirements underlined in 2800 iranian standard, research to achieve the optimized results in lightweight concrete production seems inevitable. since, one of the commonly used methods for producing the light eight concrete, utilizes the light weight aggregates with significant role i...

background: biological shielding of nuclear reactors has always been a great concern and decreasing the complexity and expense of these installations is of great interest. in this study, we used datolite and galena (daga) minerals for production of a high performance heavy concrete. materials and methods: datolite and galena minerals which can be found in many parts of iran were used in the con...

A novel, non-covalent polymeric nanosheet has been produced through small molecule self-assembly; the structure has been characterized by solution NMR, solid-state NMR, powder XRD and AFM.

polymeric yarns for reinforcing cement composites have got great interest in all over the world. in this research the performance of bonding between nylon tire cord grad yarns, and one kind of cement composite called fine grained concrete was studied. two kinds of nylon cord yarns, nylon 6 and 66, with different finesse were selected. the durability of yarns with time in alkaline media was inve...

Abstract. The Polymer concrete is first established in the year of 1950s and gained popularity 1970s repair works, building cladding floors, as precasts components. has found applications particularly specialised sectors due to its qualities such high compression strength, quick curings, specific strengths, chemical resist. objective this experiment use destructive non-destructive experiments a...

This Engineer Technical Letter (ETL) discusses the special problem areas and concerns related to RCC construction in order to assure that the concrete properties required are ultimately realized in the completed structure. A quality RCC product requires a coordinated effort between the structural designer, the materials engineer, the materials laboratory, and those responsible for field quality...

Signature schemes that are derived from three move identification schemes such as the Fiat-Shamir, Schnorr and modified ElGamal schemes are a typical class of the most practical signature schemes. The random oracle paradigm [1,2,12] is useful to prove the security of such a class of signature schemes [4,12]. This paper presents a new key technique, “ID reduction”, to show the concrete security ...