The length of real solar year has some variations because of different factors, in a way that is very difficult to compute it for each year. The solar calendar, therefore, must be based on the average length of the solar year. This length, i.e. tropical year, is not an integer (365.24219879 days). Thus in solar calendar, we must make use of some special intercalation in order to get the length of calendar year as much close to the length of natural year as possible.The present Iranian calendar is a solar one. But the law is silent about the length of solar year and the method of intercalation, the fact that has brought about discrepancies among the experts in Iranian calendar.Believing in the necessity of accepting the average length of solar year, the author has tried to find the best intercalation and appropriate cycle(s), by using a computer program. As the result of these computations, a 2820-year cycle, with its special system of leap years, is the best possible, since it prepares a cycle for any ideal solar calendar, including the present Iranian calendar. The author claims that this cycle (with its method of intercalation) would put an end to discrepancies among the scholars.

Biological method for controlling (use of plant polyphenols) the postharvest fungi diseases has been suggested as an environmentally friendly method. However the principal problems of plant polyphenols application as fungicide is their rapid decomposition in normal environmental conditions by temperature, oxygen and light. One of the best solutions for this problem is encapsulation or intercalation them into nanoparticles In this regard, the pomegranate fruit peel and clove rich of polyphenols was extracted by water and methanol and was intercalated into the layers of silica nanoparticles (montmorillonite) and his antifungal effect was tested via broth dilution method and agar well-diffusion method against blue mold fungi. The XRD, FTIR and DLS analyses confirmed completely intercalation of pomegranate peel extract into interlayer of montmorillonite. The results showed that in the broth dilution method, nanosilica particles alone had antifungal effect similar to commercial fungicide. And intercalation extract into nanoparticles did not affect its antifungal effects. In the contrast,, in agar well-diffusion method, intercalation the extract into nanoparticles increased its inhibitory effect very significantly (p

Nanocomposites based on high-density polyethylene-grafted maleic anhydride (HDPE-g-MA) were prepared by in situ reactive melt mixing using a twin-screw extruder. The effects of different modified clays and maleic anhydride content on intercalation and mechanical properties were studied. The nanocomposites were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy techniques and tensile testing. The results show that clay I.30TC is suitable for preparation of HDPE-g-MA/clay nanocomposites. Grafting HDPE with MA contributed to higher degree of intercalation in clay particles and increases the tensile modulus of nanocomposite. MA content should be maintained at a certain level to improve the extent of intercalation. During the process, grafted maleic anhydride groups on HDPE backbone are converted to acid pendant groups. In order to determine the extent of cross-linking as a function of MA content, the gel content of the samples were measured. A significant improvement in the tensile modulus of the HDPE/clay nanocomposites was observed without changes in tensile strength and elongation-at-break values.

In this study, firstly bentonite from Tang-e Quchan mine was collected, and its montmorillonite content was mostly separated from impurities. Montmorillonite was used in the synthesis of Al-PILC to investigate the influence of pH during the intercalation process on properties of pillared clays. The pH of intercalation was initially 4.1, and Al/Clay ratio was determined 4 mmole/g clay. The pH of the intercalation stage was changed by adding some droplets of dilute hydrochloric acid. Al-PILCs were heated at 400 °C and were characterized using X-ray diffraction and adsorption/desorption isotherms of nitrogen. The results showed that at pH values between 3.7 and 4.1, Al-PILCs had an acceptable basal spacing and surface area. The highest surface area and the basal spacings were 18.04 0A and 160 m2/g, respectively which was obtained for pillared interlayered clay with intercalated pH of 3.8

Novel phenanthro-triazine-3-thiol derivatives were designed as potential DNA intercalators and Bcl-2 inhibitors. After being synthesized, the compounds were evaluated for their cytotoxic activity against MOLT-4 (human acute lymphoblastic leukemia) and MCF-7 (human breast adenocarcinoma) cells by MTT assay. P1 (bearing hydrogen substitution) was the most potent derivative against MOLT-4 with an IC50 value of 7.1 ± 1.1 μM, whereas P11 (bearing phenyl substitution) demonstrated considerable cytotoxicity against MCF-7 with an IC50 value of 15.4 ± 2.9 μM. Compounds P7, P8, P14 and P15 exhibited moderate cytotoxic effects. Furthermore, to confirm the potential DNA intercalation and Bcl-2 inhibitory activities of phenanthro-triazine scaffolds, molecular docking analysis was performed. Molecular docking studies indicated that these compounds not only bind to DNA by intercalation mainly through stacking interactions but also are well accommodated in the active site of Bcl-2. Therefore, P1 and P11 having phenanthro-triazine-3-thiol scaffold could be presented as cytotoxic agents with dual DNA intercalation and Bcl-2 inhibitory activities.

FT-SERS (Fourier Transform Surface Enhanced Raman Scattering) of adriamycin and its complex with DNA is reported. It is shown that in agreement with previous Raman studies the interaction of adriamycin with DNA takes place through an intercalation mechanism. The presence of a new band at 731 cm-1 suggests that ring D of adriamycin is not involved in the intercalation process.

Many anticancer drugs in clinical use interact with DNA through intercalation, which is process that starts with the transfer of the intercalating molecule from an aqueous environment to the hydrophobic space between two adjacent DNA base pairs. In general, intercalatig agents are two types: monofunctional and bifunctional. Monofunctional intercalators contain one intercalating unit and Bifunctional intercalators (bis-intercalators) contain two intercalating units, normally cationic, separated by a spacer chain that must be long   enough to allow double intercalation taking into account the neighbour exclusion principle.

Periods are the most important parts of the Iranian calendars. During the Achaemenien dynasty the lunisolar 19-year system was in official use. The lunisolar 25-year cycle of intercalation was in use by the Seleucid.At first the Arsacid used the same way of the Seleucid, but then used the solar calendar with the era of the first king of the dynasty. During the Sassanid era the Arsacid calendar became popular in two forms of common civil (or khirājī) and Vahijkik (one month intercalation in every 120 years).The period of leap years in every 120 years during the Sassanid era have been studied by Iranian researchers and orientalists. The doubled intercalary which was two months simultaneously in 461 A.D. during Firūz monarchy (the son of Yesdgerd II, 484-459 A.D.), has been the turning point of intercalary not only in the Iranian calendar but also in other Islamic possessions for about 600 years.The new way of intercalary which was applied in Jalālī calendar is an honor for the Iranian mathematicians and astronomers which found it about 1000 years ago.Unfortunately, there would never be a periodical usage for the leap years, even in the present formal Hejira solar calendar.The 2820-year intercalation period is one of the new innovations which presented by some modern researchers, but its way lacks accuracy and efficiency of the 128-year historical intercalation period.

Kopet Dagh Basin is located on the northeast of Iran, extending over Iran, Turkmenistan and Afghanistan with a west-northwest to east-southeast trend. The Iranian part of the basin is located between 61°14ˊ and 54°00ˊE and 38°15ˊ and 35°38ˊ N. It constitutes the second most important hydrocarbon province of Iran after Zagros Basin. Cretaceous sediments are well developed and extensively exposed in this basin. In order to study the Biostratigraphy of Sarcheshme and Sanganeh Formations, the calcareous nannofossil assemblages have been investigated in two stratigraphic sections. Shokri (2000), Hadavi and Shokri (2000), Hadavi and Bodaghi (2000 & 2009), Dehghan (2002), Mahanipour et al. (2011a,b & 2012) and Mahanipour and Kani (2015) studied the calcareous nannofossil biostratigraphy of Sarcheshme or Sanganeh Formation.
Material & The studied sections, the Qaleh Jegh section (located at a distance of 35 km to the northeast of Bojnord, on the Baba Boland mountain; N37°47ˊ57˝ and E57°16ˊ53˝) and Yazdan Abad section (located at north of Yazdan Abad village; N37°55ˊ34˝ and E57°35ˊ10˝). Sarcheshmeh Formation conformably overlies the Tirgan Formation and is in turn overlain by the Sanganeh Formation in both sections and Atamir Formation conformably overlies the Sanganeh Formation.
Sarcheshmeh Formation measures 2660 m in Qaleh Jegh section and comprises argillaceous limestone (with limestone intercalations) in lower part and shale (with limestone intercalation) in upper part. A fossiliferous limestone separates the Sarcheshmeh and Sanganeh. Sanganeh Formation measures 1400 m and consists of siltstones (with sandstone, shale or limestone intercalation) in lower part and shale containing chert nodules (with siltstone intercalation) in upper part.
At Yazadn Abad section the 655 m thick succession of Sarcheshmeh Formation consists of alternating argillaceous limestone and limestone in lower part and calcareous marl, marl and argillaceous limestone in upper part. A fossiliferous limestone separates Sarcheshmeh and Sanganeh formations. Sanganeh Formation is 485 m thick comprising siltstones with sandstone, marl (with argillaceous limestone or limestone intercalation).
A total of 1286 samples (1006 from Qaleh Jegh section and 280 from the Yazdan Abad section) were collected at about 4 m intervals. For the purpose of biostratigraphic investigations, all of the samples were processed using the gravity settling technique (Bown and Young, 1998) and the prepared slides were observed under a Leica DMLP Pol light microscope at ×1000 magnification.
Discussion of Results & Nannofossil bioevents have been utilized to biostratigraphically classify the exposed sedimentary succession based on schemes of Roth (1978; modified by Bralower et al., 1993) and Sissingh (1977; modified by Perch-Nielsen, 1985). Overall, 56 species from 28 genera of 14 families in Qaleh Jegh section, and 45 species from 26 genera of 13 families in Yazdan Abad section have been identified and their distribution recorded. Based on the index calcareous nannofossil taxa, the upper part of NC6, NC7A, NC7 (B&C) and lower part of NC8 nannofossil zones are delineated in Ghaleh Jegh and the upper part of NC5, NC6, NC7B and lower part of NC7A are recorded in Yazdan Abad. The distributions point to Early to Late Aptian time of deposition for the rocks of Sarcheshmeh Formation and Late Aptian to Early Albian for those of Sanganeh Formation in Ghaleh Jegh, while At Yazdan Abad, Sarcheshmeh Formation ranges from Late Barremian to Early Aptian and Sanganeh Formation dates Early to Late Aptian.

Nanocomposites based on butadiene rubber (BR)، (0، 3، 5 and 7 phr) organoclay (Cloisite 15A) and (0، 10، 20، 30، 40 phr) powder coating wastes، i. e.، epoxypolyester hybrid (EPH) were prepared using a laboratory-scale internal mixer in order to study the effect of organoclay and EPH content on the mechanical and morphological properties of the nanocomposite samples. Cure characteristics of the prepared compounds including optimum cure time (t90) and scorch time (t5) depicted a decrease in both mentioned factors with increasing nanoclay content and EPH loading. Intercalation of elastomer chains into the silicate layers was determined by d-spacing values calculated according to the results of X-ray diffraction (XRD) patterns. X-ray diffraction (XRD) results reveal the intercalation of elastomer chains into the clay galleries. This phenomenon was also confirmed according to the scanning electron microscopy (SEM) micrographs and mechanical properties of the nanocomposite samples which were observed to be improved with addition of nanoclay and EPH content.