The conventional literature suggests a positive relationship between the expected return and the conditional volatility, but according to the empirical evidence there is not a specific and constant relationship between them. In this regard, the study investigates the role of significant characteristics of financial asset prices including time-varying conditional volatility and jump in the relationship between risk and return in Tehran stock market. For this purpose the ARJI-GARCH model which includes both features is applied and the results are compared with two more simple models i.e. GARCH-M and GARCH- JUMP.The former consists of the conditional variance and the latter has both features but with the constant probability of the jump. The empirical findings using daily data from September 9th 1997 to March 15th 2015 imply that the jump component has a significant impact, and the risk of Iran’s stock returns includes both smoothly changing variance and jump events. Therefore, the traditional GARCH-M model cannot explain correctly the relationship between risk and return in Iran’s stock market. Also, the analysis of the time-varying risk premium shows that in the short-run only the risk arising from jump is significant.

One of the important issues in the production of concrete is environmental variability that affects the concrete and elements constructed from this material. Due to the importance of different characteristics of concrete in short- and long-term conditions, this article aims to investigate the influence of initial temperature conditions of self-compacting concrete on its long-term characteristics and determine the initial optimal temperature of concrete. For these purposes, several experiments under three temperature conditions of 5, 20, and 40 degree-of-Celsius were conducted to evaluate the rheology and mechanical properties of fresh concrete in the range of 7 and 28 days. In these experiments, alternative mineral admixtures of cement such as micro-silica, fly ash, and zeolite were used to build the concrete specimens. Results demonstrate that the mechanical properties of the specimens increase with increasing initial temperature in the short term, while such properties significantly decrease in the long term compared to the specimens constructed under lower initial temperature. Moreover, the fluidity of self-compacting concrete increases with increasing initial temperature.

In the present work, the study of alumina-water nanofluid heat transfer between two concentric vertical cylinders has been done by modified Buongiorno’ s model (BM) to examine the impacts of temperature jump and slip velocity boundary conditions for a wide range of Knudsen number. Runge-Kutta-Fehlberg method, as a standard integration scheme along with a shooting method, has been chosen for solving nonlinear ordinary differential equations (ODEs) along with boundary conditions. The main concentration of this paper is on the temperature jump since the slip velocity has been extensively examined in many studies. The presence of temperature jump boundary condition by varying Knudsen number was considered to investigate the effects of the bulk mean nanoparticle volume fraction ϕ B, mixed convection parameter Nr, buoyancy parameter Ng, and heat flux ratio ε on the total dimensionless heat transfer coefficient HTC and the dimensionless pressure gradient Ndp. The obtained results indicate that temperature jump boundary condition plays a pivotal role in temperature profile, heat transfer coefficient and pressure drop; for instance, the negligence of temperature jump near walls causes to undervalue heat transfer coefficient in continuum flow regime and overestimate it in slip flow regime

Temperature is one of the important thermodynamic meteorological elements the change of which can cause many physical, chemical and environmental variations. The history of measuring temperature is relatively long compared to that of other elements in meteorology. In spite of some evidence and experts" belief about the global warming in the years 1947 and 1948, the idea of stationary climatic condition persisted till 1970s.Many research done at national, regional, and global levels indicate an increase in temperature in many parts of the world. In other words they prove an increase in the mean global temperature. Although there is a marked increase in maximum temperature in many parts of the world owing to its lower increase rate, compared to that of minimum temperature, DTR has decreased. The results obtained for maximum, minimum, and mean temperatures are quite different from one another. Positive trend for minimum temperature in majority of Iranian synoptic stations especially in those located in cities with high urban growth rate, are remarkable. For instance, it is strong in Esfahan. Moreover, we found a jump in annual temperature series in the 1970s that is consistent with the jump in many places in the world. DTR in large cities like Esfahan, Shiraz, and Tehran has decreased significantly. In this regard, a 4°C decrease in Esfahan can be noticed. In addition to some exceptions, quality and quantity of trends are also discussed.

The rarefaction effects on the catalytic decomposition of NH3 in ruthenium-coated planar microchannels is numerically simulated in the Knudsen number range 0.015-0.03. A colocated finite-volume method is used to solve the governing equations. A concentration jump model derived from the kinetic theory of gases is employed to account for the concentration discontinuity at the reactive walls. A detailed surface reaction mechanism for ammonia decomposition on ruthenium along with a multi-component species diffusion model are used to study the effects of concentration jump coupled with velocity slip and temperature jump on the walls. The velocity-slip, temperature-jump and concentration-jump boundary conditions have miscellaneous effects on flow, temperature and species concentration fields. The results suggest that the velocity-slip boundary condition only slightly influences the species distribution at the edge of the Knudsen layer as well as inside the channel, while the temperature-jump boundary condition affects the heat and mass transfer characteristics the most. The concentration-jump effect, on the other hand, can counter balance the temperature-jump effects in some cases.

The ability of plant communities in natural ecosystems to modify temperature has become increasingly important due to the profound impacts of global climate change, particularly in arid regions. However, previous studies have provided limited information on the long-term temperature feedback of these plant communities and the biotic drivers behind these changes. This study aimed to determine the functional traits and types of plant communities as biotic drivers of land surface temperature (LST) at the plant community scale, with a focus on identifying co-functioning communities in the Sirjan region of Kerman Province. To achieve this, we utilized the MODIS-LST 8-day composite product at the plant community scale and measured functional traits of dominant species through field operations. The results revealed that leaf dry matter content (LDMC), maximum height (MH), and leaf width (LW) traits significantly reduce LST. Additionally, cluster analysis indicated that the plant communities in the study area can be classified into five functional groups, which fall into two co-function categories. The S-strategized co-function (e.g., 26 communities), characterized by high LDMC values and a combination of abrupt and trend feedback in LST, was found to be more effective than the R-strategized co-function (e.g., 13 communities), which exhibited only trend feedback. Therefore, it can be argued that extreme temperatures, as a global concern, can be mitigated through careful selection of vegetation based on functional traits and strategies. This approach, particularly through rangeland improvement practices using species such as Astragalus spachianus, Cornulaca monacantha, and Launaea acanthodes, could play a significant role in addressing this challenge.

The current study aimed to optimize artificial insemination in aged broiler breeder hens in two experiments. In the first experiment, the effect of (two) different diluted semen temperatures (5 and 25 °C) of Hubbard rooster (40 roosters, 58 weeks of age) on fertility, hatchability and sperm penetration (SP) rate in the perivitelline layer of Hubbard hen (180 hens) were investigated. In the second experiment, three (different) sperm concentrations (100 (C100), 200 (C200), and 400 (C400) million sperm in 0.25 mL per hen) of Hubbard roosters (40 roosters, 62 weeks of age) on fertility, hatchability and SP rate of Hubbard broiler breeder hens (270 hens) were explored. In the first experiment, the results showed that the temperature of 5 °C of diluted semen compared to the 25 °C, increased percentage of hatchability of set eggs, hatchability of fertile eggs, and SP and decreased early embryonic mortality. The results of the second experiment showed the highest percentage of fertility and SP rate were observed at treatment C400. Also, in this experiment that highest percentage of hatchability of set eggs and hatchability of fertile eggs and lowest early embryonic mortality were observed at treatment C400. Return on investment (ROI) of the treatments C200 and C400 was approximately 2.9 and 1.4, respectively. In overall, the results of this study showed that (in attention to ROI and hatchability) to optimize artificial insemination of aged broiler breeder hens we can use a sperm concentration of 200 to 400 million in 0.25 mL per hens at 5 °C.

In this study, the life history characteristics of Trichogramma euproctidis (Girault), an established egg parasitoid species in southwestern Iran, parasitizing Helicoverpa armigera (Hubner) were examined at 18, 21, 24, 27, 30, and 33 °C. The results showed that different constant temperatures significantly affected the number of parasitized eggs, development time, sex ratio, tibial length, number of parasitoids per host egg, progeny longevity, and fecundity. T. euproctidis failed to complete development at 18 °C, the lowest temperature tested. The mean developmental duration from egg to adult female decreased from 15.33 days at 21 °C to 7.25 days at 33 °C. An average of 188-degree days was required to complete development above the lower threshold temperature (7.2 °C). Survivorship was 96.20, 97.20, 98.33, 85.46, and 82.22 % at 21, 24, 27, 30, and 33 °C, respectively. The mean longevity of T. euproctidis ranged from 11.60 days at 21 °C to 4.57 days at 33 °C. Mean total progeny ranged from 19.50 / female at 33 °C to 168.70 / female at 21 °C. Data analysis demonstrated that different constant temperatures had a significant effect on the net reproductive rate (R0), intrinsic rate of increase (r), finite rate of increase (λ), and generation time (T). The intrinsic rate of increase (r) improved with temperature from 0.240/day at 21°C to 0.370/day at 27 °C and then decreased at higher temperatures. Generation time decreased from 16.90 days to 7.53 days with increasing temperature. The optimal temperature for development and reproduction of T. euproctidis was 27 °C. The results of this study showed that this strain of T. euproctidis appears to have the potential to be utilized in integrated management programs targeting H. armigera.