Evaluating delay factors in the construction and operation of port operational areas (case study: Shahid Rajaee port complex)

A significant part of the annual budget of developing countries is allocated to civil projects and the construction industry. In Iran, between 30% and 40% of the total budget of the country `is allocated to this industry. However, the implementation of these projects is often faced with several problems that cause delays and increase costs. The main objective of this research is to identify, analyze, and prioritize factors effective in delays in the construction of port operational area and to offer suggestions for preventing or reducing these delays. The statistical population of the study consists of employers,investors, consultants and contractors involved in the construction of port operational areas in Iran. Data were collected through a questionnaire and were then analyzed using structural equation modeling in VPLS software. Results showed the most effective factors of the delay in the construction of port operational areas to be inadequate monitoring(11%), poor planning and time scheduling (19%), improper allocation of resources (24%), cash flows changes(28%), failure to fund the projects on time (16%)and other factors (27%). These results can assist companies and legal authorities involved in the construction of port operational areas in Iran in making the right decisions based on the importance and effectiveness of each delay factor.Keywords: Delay Factors, Port Construction Projects, Project Management

The Effect of Acupressure at GB-21 and SP-6 Acupoints on Anxiety Level and Maternal-Fetal Attachment in Primiparous Women: a Randomized Controlled Clinical Trial

Background: Delivery is one of the most stressful events in women’s life. Excessive anxiety, in turn, increases delivery and pregnancy complications. Mother’s positive experience of delivery leads to more effective maternal-fetal attachment in the first few hours of birth. Objectives: The present study aimed to compare the effects of acupressure at two different acupoints on anxiety level and maternal-fetal attachment in primiparous women. Materials and Methods: In this study, 150 primiparous women were allocated to acupressure at GB-21 acupoint, acupressure at SP-6 acupoint, and control group. The women in their active phase of delivery were enrolled in the study and pressure was applied to the acupoints for 20 minutes. Mother’s anxiety level was assessed using Spielberger’s questionnaire before and one hour after the intervention. In addition, maternal-fetal attachment behaviors were evaluated using Avant’s questionnaire during the first breastfeeding. Then the data were introduced to the SPSS (v. 13) and were analyzed using t test and one way ANOVA. Results: The results revealed no significant difference among the three groups regarding the anxiety level before the intervention (P > 0.05). One hour after the intervention, this measure was significantly lower in the intervention groups in comparison to the control group (P 0.05). Moreover, maternal-fetal attachment was higher in the intervention groups in comparison with the control group (P < 0.001). Conclusions: Acupressure at both acupoints reduced anxiety level and increased maternal-fetal attachment. This method can be easily used in the delivery room

LH pulse frequency and the emergence and growth of ovarian antral follicular waves in the ewe during the luteal phase of the estrous cycle

<p>Abstract</p> <p>Background</p> <p>In the ewe, ovarian antral follicles emerge or grow from a pool of 2–3 mm follicles in a wave like pattern, reaching greater than or equal to 5 mm in diameter before regression or ovulation. There are 3 or 4 such follicular waves during each estrous cycle. Each wave is preceded by a peak in serum FSH concentrations. The role of pulsatile LH in ovarian antral follicular emergence and growth is unclear; therefore, the purpose of the present study was to further define this role.</p> <p>Methods</p> <p>Ewes (n = 7) were given 200 ng of GnRH (IV) every hour for 96 h from Day 7 of the estrous cycle, to increase LH pulse frequency. Controls (n = 6) received saline. In a second study, ewes (n = 6) received subcutaneous progesterone-releasing implants for 10 days starting on Day 4 of the cycle, to decrease LH pulse frequency. Controls (n = 6) underwent sham surgery. Daily transrectal ovarian ultrasonography and blood sampling was performed on all ewes from the day of estrus to the day of ovulation at the end of the cycle of the study. At appropriate times, additional blood samples were taken every 12 minutes for 6 h and 36 min or 6 h in studies 1 and 2 respectively.</p> <p>Results</p> <p>The largest follicle of the follicular wave growing when GnRH treatment started, grew to a larger diameter than the equivalent wave in control ewes (P < 0.05). Mean serum estradiol and progesterone concentrations were higher but mean serum FSH concentrations were lower during GnRH treatment compared to control ewes (P < 0.05). The increased serum concentrations of estradiol and progesterone, in GnRH treated ewes, suppressed a peak in serum concentrations of FSH, causing a follicular wave to be missed. Treatment with progesterone decreased the frequency of LH pulses but did not have any influence on serum FSH concentrations or follicular waves.</p> <p>Conclusion</p> <p>We concluded that waves of ovarian follicular growth can occur at LH pulse frequencies lower than those seen in the luteal phase of the estrous cycle but frequencies seen in the follicular phase, when applied during the mid-luteal phase, in the presence of progesterone, do enhance follicular growth to resemble an ovulatory follicle, blocking the emergence of the next wave.</p

Towards Sustainability Assessment of the Built Environment: A Classification of the Existing Challenges

The application of sustainability assessment in a decision context is associated with various challenges that explain why the transition to action-oriented knowledge still needs to be fulfilled. Therefore, this paper aims to explore the associated challenges in sustainability assessment in the decision context of the built environment. Several publications are reviewed to provide a systemic understanding of the associated complexities. The challenges in sustainability assessment in the built environment are categorized at different levels, from understanding to measurement and implementation. The challenges are further categorized into definition, context, interpretation, data, measurement methods, uncertainties, indicators and indices, results, coordination, conflicts, and action-oriented knowledge. Moreover, according to the nature of each challenge, they are classified into epistemological, methodological, and procedural challenges. The novelty of this review is that it reviews and reports almost all fragmentedly reported challenges in sustainability assessment of the built environment in the literature within a holistic framework that provides a clear understanding of the state of the art and second discusses them within an integrated framework (the Sustainability Assessment Network) including the position of active-role players to resolve them, including strategists, scientist, and stakeholders

Intraguild predation by Hippodamia variegata (Col.: Coccinellidae) on the parasitoid wasp, Lysiphlebus fabarum (Hym.: Braconidae)

Intraguild predation is defined as killing and eating another predator species as potential competitors that depends upon the same or limited resources. In this study, intraguild predation between the ladybird Hippodamia variegata Goeze and the parasitoid wasp Lysiphlebus fabarum (Marshall) was investigated in association with cotton aphid, Aphis gossypii, on cucumber plants. Host preference for healthy or previously parasitized aphids in third instar larvae and adult females of H. variegata was studied in a choice access situation as well as in a Y-tube olfactometer bioassay. We cut an antenna of each experimental aphid to reliably distinguish  the parasitized aphids from healthy ones. All experiments were performed at 22±1°C, 60%–70% RH, and a 16:8 (L:D) photoperiod. Based on the pre-test results, cutting the antenna of aphids, did not significantly affect the host preference of adults or third instar larvae of ladybirds. In a choice access test, female ladybirds significantly preferred healthy aphids to previously parasitized ones (24 and 72 hours: t =2.15, df =1,18, P =0.04 and t =6.35, df =1,18, P <0.001, respectively), but third instar larvae behaved differently  (t =0.58, df =1,18, P =0.56). According to olfactometer test results, female ladybirds preferred neither healthy aphids nor parasitized ones (χ2 =1.6, df =1,19, P =0.21). It is concluded that preference for healthy aphids over parasitized ones by adult female of H. variegata  facilitates the simultaneous application of the both biocontrol agents, H. variegata and L. fabarum

Genomic Selection of Purebred Animals for Crossbred Performance in the Presence of Dominant Gene Action

The primary objective of this study was to assess the performance of different genomic prediction models applied to the selection of purebreds for crossbred performancebased on high-density marker data. Our results suggest that in the presence of dominant gene action, selection based on the dominance model is superior to both the a breed-specific allele model and an additive model in terms of maximizing crossbred performance through purebred selection, especially when training is not updated each generatio

Experimental investigation of performance improvement of double-pipe heat exchangers with novel perforated elliptic turbulators

In the present study, heat transfer and thermal efficiency of double-pipe heat exchangers with novel Double-Perforated Inclined Elliptic (DPIE) turbulators were experimentally investigated. The range of Reynolds number was between 5000 and 18,000 under turbulent flow regime. The inclination angle of the elliptic inserts , and the perforation diameters (d) varied from 15° to 25°, and 0.5 mm < d < 1.5 mm, respectively. The perforated vortex generators can significantly increase the flow perturbations and disrupt the thermal boundary layer to enhance the heat transfer without noticeable impact on the friction loss. The experiments revealed that the average Nusselt number was increased by 217.4% by using DPIE turbulators compared to the tube without vortex generators. The recirculations through the perforations of the elliptic turbulators, increase the fluid mixing between the walls and the core area. The maximum thermal efficiency parameter of 1.849 was obtained for DPIE vortex generators with d/b = 0.25 and . The Friction factor increment of 14.0% was observed for the double perforated elliptic turbulators with d/b = 0.25 compared to the typical elliptic inserts without perforations. It was found that the heat transfer is increased around 39.4% by using DPIE inserts with d/b = 0.25 compared to the typical louvered strips without perforations. The main benefits of the proposed novel turbulators are their much higher thermal efficiency compared to the previous turbulators at wide range of Reynolds numbers, and their simple installation together with low manufacturing costs

Experimental investigation of heat transfer enhancement of a heat exchanger tube equipped with double-cut twisted tapes

An Experimental study has been performed to investigate the heat transfer characteristics and friction factors of fluid flow through a heat exchanger tube equipped with double-cut twisted tapes (DCTT) with different cut ratios. The rectangular cuts have ratio values ranging from 0.25 to 0.90. This study is carried out under turbulent flow regime (5000 ≤ Re ≤ 15,000) and water is selected as the working fluid. Due to swirl flows, DCTTs lead to more fluid mixing between the tube wall and core regions, which has considerable effects on the heat transfer inside heat exchanger tubes. The results show that by increasing the cut ratio from 0.25 to 0.90, the Nusselt number (Nu) enhances up to 177.4%. The thermal performance varies from 1.63 to 1.44 for the cut ratio of 0.90. Three correlations based on the experimental data are developed to predict Nu, f and as functions of design parameters under turbulent flow regimes. These results provide evidence that the use of DCTTs is an effective technique to enhance heat transfer in a heat exchanger tube

A Numerical Study on the Effects of Nanoparticles and Stair Fins on Performance Improvement of Phase Change Thermal Energy Storages

Using nano-enhanced phase change materials is a widespread passive method to improve the melting performance, and also the storage capacity of the thermal energy storage units. In this study, the effects of CuO nanoparticles (0≤φ≤1.5%) and new proposed stair fins on the efficiency improvement of latent heat thermal energy storage units are investigated. The stair fins are arranged in both upward and downward directions from the heated walls and the stair ratio is in the range of 0.67≤b/c≤4.0. One of the vertical walls of the PCM enclosure is subject to uniform temperature and the other three walls are insulted. The numerical results show that by adding nanoparticles with volume concentration of φ=1.5% for b/c = 0.67 to the flow, the energy storage capacity is enhanced by 9.1% compared to the pure PCM with downward fins. The maximum energy storage capacity of 474.1 kJ is achieved by using descending stair fins with b/c = 4.0 and φ=1.5% which is much higher compared to the cases without nano additives. Besides, the melting performance is significantly improved by adding the nanoparticles. In fact, nanoparticles improve the thermal conductivity of the fluid and also act as a heat sink to absorb the heat from the fins. The downward fins with larger stair ratios (b/c = 4.0) perform significantly better than the upwards ones which is because of the free convection effects and the recirculations flows on the upper face of these fins

Ammonia emissions from cattle urine and dung excreted on pasture

Twelve cattle were kept for three days in a circular area of 16 m radius on short pasture and fed with freshly-cut pasture. Ammonia (NH&lt;sub&gt;3&lt;/sub&gt;) emissions from the urine and dung excreted by the cattle were measured with a micrometeorological mass-balance method, during the cattle presence and for 10 subsequent days. Daily-integrated emission rates peaked on Day 3 of the experiment (last day of cattle presence) and declined steadily for five days thereafter. Urine patches were the dominant sources for these emissions. On Day 9, a secondary emissions peak occurred, with dung pats likely to be the main sources. This interpretation is based on simultaneous observations of the pH evolution in urine patches and dung pats created next to the circular plot. Feed and dung samples were analysed to estimate the amounts of nitrogen (N) ingested and excreted. Total N volatilised as NH&lt;sub&gt;3&lt;/sub&gt; was 19.8 (± 0.9)% of N intake and 22.4 (± 1.3)% of N excreted. The bimodal shape of the emissions time series allowed to infer separate estimates for volatilisation from urine and dung, respectively, with the result that urine accounted for 88.6 (± 2.6)% of the total NH&lt;sub&gt;3&lt;/sub&gt; emissions. The emissions from urine represented 25.5 (± 2.0)% of the excreted urine-N, while the emissions from dung amounted to 11.6 (± 2.7)% of the deposited dung-N. Emissions from dung may have continued after Day 13 but were not resolved by the measurement technique. A simple resistance model shows that the magnitude of the emissions from dung is controlled by the resistance of the dung crust