535 research outputs found
An Investigation of the Effect of Ventilation Inlet and Outlet Arrangement on Heat Concentration in a Ship Engine Room
Τhe ventilation in the ship engine rooms is an essential issue concerning finest performance of engines and diesel generators as well as electric motors. The present study has aimed at the analysis of temperature distribution inside the ship main engine room. In the same way, attempts have been made to identify those points with considerable thermal concentration in main engine room space, so that proper ventilation systems could be engineered and utilized and favorable thermal conditions could be realized. The CFD approach has been utilized in order to analyze impact of the designed ventilation system on the temperature distribution pattern. The Inlet layout and area have been analyzed under a variety of scenarios in order to decrease the average temperature and eliminate the heat concentrations in various points of the engine room. The temperature distribution and location and area of ventilation air inlet have been studied in different modes resulted in temperature distribution pattern, heat concentration outline and average volumetric temperature level in each mode. The results indicated that considerable circulating air volume is required compared to those levels suggested by common practices, calculations and standards in order to eliminate the heat concentration
Music distraction among young drivers: analysis by gender and experience
The aim of this study was to quantify the probability of committing a speed infraction by young drivers and to investigate to what extent listening music could affect young drivers’ emotions as well as their driving performances at the wheel. To achieve this aim, employing Bayesian networks, the study analysed different music styles, in which they resulted in sample drivers’ speed infractions. Gender and drivers’ experiences at the wheel were the other factors, which were taken into account when interpreting the study results. Variables taken into account in this study included type of music whilst driving, gender of drivers, and drivers’ driving experiences. These variables further incorporated into the study of other telemetric variables including acceleration, number of revolutions per minute (RPM) of the engine, brake, traffic, and other types of infractions other than speed, which were considered as dependent variables. A driving simulator was used, and different driving simulation studies were carried out with young people aged between 20 and 28 years. Each participant carried out three simulations by listening to different type of music in each journey. The study defined a conceptual model in which the data were analysed and evaluated mathematically through Bayesian networks. A sensitivity analysis was performed to evaluate the influence of music on driving speed. Based on the different variables, the study further analysed the probability of speed infractions committed by drivers and their adequate speed. The range of frequency probabilities varied between 96.32% (which corresponds to experienced male drivers who do not listen to music) and 79.38% (which corresponds to less-experienced female drivers who listen to music), which resulted in their happiness or aggression.FEDER (Fondo Europeo de Desarrollo Regional) for developing Castilla y Le´on´s region. *e title of the project is “Modelizaci´on mediante t´ecnicas de machine learning de la influencia de las distracciones del conductor en la seguridad vial-Modeling the influence of driver´s distractions on road safety through machine learning techniques.” Ref. BU300P1
Scotopic contrast sensitivity and glare after accelerated corneal cross-linking
Background: The aim was to assess one-year changes in uncorrected and corrected contrast sensitivity (CS) and glare under scotopic conditions after accelerated cross-linking (CXL) using the 18 mW/cm2 protocol for the treatment of progressive keratoconus and compare results with unoperated controls. Methods: In this non-randomised clinical trial, 30 eyes were enrolled in the CXL group and 30 were assigned to the control group. Scotopic CS at spatial frequencies (SFs) of 0.5, 1.1, 2.2, 3.4, 7.1 and 15 cycles per degree (cpd) were assessed using the MonCv3System (Metrovision, Pérenchies, France) under scotopic conditions (0.5 lux) at baseline and at six and 12 months. Results: The mean ages of the participants in the CXL and control groups were 24.32 ± 5.17 and 30.93 ± 7.43 years, respectively (p < 0.001). After adjusting for age, changes in uncorrected and corrected CS and glare were similar in the two groups (all p > 0.05) except for corrected CS at SF 7.1 cpd (1.45 ± 4.31 versus 3.21 ± 4.69 dB, p = 0.010) and 15 cpd (1.12 ± 4.63 versus 3.03 ± 5.48 dB, p = 0.007), which were reduced as an effect of CXL. Based on covariate analyses, among corrected CS indices, corrected CS7.1 and CS15 were related to CXL and their baseline values (all p < 0.050). Uncorrected CS in all SFs and uncorrected and corrected glare were related to their pre-operative values (all p < 0.001). Conclusion: Accelerated CXL can reduce scotopic corrected CS at SFs higher than 7.0 cpd in cases with better baseline values of these parameters. Changes in uncorrected CS and glare are only a factor of baseline values and the indices reduce in cases with better baseline values after one year. © 2017 Optometry Australi
Hyperglycemia decreased medial amygdala projections to medial Preoptic area in experimental model of diabetes mellitus
In Wistar rats, reproductive behavior is controlled in a neural circuit of ventral forebrain including the medial amygdala (Me), bed nucleus of the stria terminalis (BNST) and medial preoptic area (MPOA) via perception of social odors. Diabetes Mellitus (DM) is a widespread metabolic disease that affects many organs in a variety of levels. DM can cause central neuropathies such as neuronal apoptosis, dendritic atrophy, neurochemical alterations and also causes reproductive dysfunctions. So we hypothesized damage to the nuclei of this circuit can cause reproductive dysfunctions. Therefore in this project we assessed diabetic effect on these nuclei. For this purpose neuron tracing technique and TUNEL assay were used. We injected HRP in the MPOA and counted labeled cells in the Me and BNST to evaluate the reduction of neurons in diabetic animals. Also, coronal sections were analyzed with the TMB histochemistry method. Animals in this study were adult male Wistar rats (230 ± 8g) divided to control and 10-week streptozotocin-induced diabetic groups. After data analysis by SPSS 16 software, a significant reduction of HRP-labeled neurons was shown in both Me and BNST nuclei in the diabetic group. Moreover, apoptotic cells were significantly observed in diabetic animals in contrast to control the group. In conclusion, these alterations of the circuit as a result of diabetes might be one of the reasons for reproductive dysfunctions. © 2015 Tehran University of Medical Sciences. All rights reserved
Advanced analysis of PRVEP in anisometropic amblyopia
Introduction: to identify the pattern-reversal visual evoked potential (PRVEP) waveform descriptor by evaluating discrete wavelet transform (DWT) in order to optimize stimulus in the diagnosis of anisometropia amblyopia. Materials and Methods: The PRVEP testing was performed for 31 normal individuals and 35 patients with amblyopia. The stimuli were consisted of spatial frequencies of 1, 2, and 4 cycles per degree (cpd) and contrast levels of 100, 50, 25, and 5. The results were analyzed in the dimensions of time and time-frequency. DWT descriptor were extracted at level 7 (7P descriptor) for Haar, Daubechies 2, Daubechies 4, Symlet 5, Biorthogonal 3.5, Biorthogonal 4.4, and Coiflet 5 wavelets for 12 stimuli and compared between the two groups. The correlation between different spatial frequencies at the same contrast level and the similarities between reconstructed signals and original waveforms were evaluated. Results: There were a significant reduction in P100 amplitude and a significant elevation in latency among the patient group. In the patients with amblyopia, 7P descriptor decreased in all analysis except for the frequency of 4 cpd and the contrast of 5 using bior4.4. No significant correlation was observed between different frequencies at a special contrast; however, there was a significant correlation between reconstructed signals and the original ones. Conclusion: The 7P descriptor could be used to distinguish between normal and abnormal signals in anisometropia amblyopia. Considering the results, DWT with coif5, db4, bior4.4, and bior3.5 wavelets can be utilized as a good indicator for selecting optimum stimulus. © 2018, Mashhad University of Medical Sciences
Smoking stages, prevalence of drug abuse and role of associated psychological and social factors: A study on male high school students in Ilam city
Background & Aims: There are limited information about prevalence of smoking, drug abuse and its associated factors amongst Iranian students. The present study aimed to determine prevalence of smoking and drug abuse amongst male high school students in Ilam and the role of associated psychological and social factors. Method: Overall, 1000 male high school students were recruited using a multi-stage sampling method. A self-administered questionnaire was used for data gathering. Chi-square test and logistic regression model were used for univariate, multivariate and interactions analyses. Results: Mean age of students was 16.2 years. The prevalence of experimenter and regular smokers were 11.4 (95 CI: 9.3 -13.4) and 1.3 (95 CI: 0.5-2.0) respectively. Prevalence rates of alcohol, opium, Tramadol, Hashish, Ecstasy and methamphetamine abuses were 11.1 (9.1-13.0), 2.8 (1.7-3.8), 7.6 (5.9-9.2), 3.3 (2.1-4.4), 2.7 (1.6-3.7), and 2.1 (1.1-3.0) respectively. The logistic regression model showed a significant relationship between having a smoker friend (AOR: 1.99), self-injury (AOR: 2.35), peer pressure (AOR: 2.37) and Tramadol abuse (AOR: 3.00) and different stages of smoking. None of the considered interactions had significant effect. Conclusions: Although, prevalence of smoking in Ilam high school students was less than the corresponding reports from other provinces in Iran, drugs abuse followed the same pattern as the other provinces. In addition, psychosocial variables had an important role in adolescents smoking
Investigation on Quality Properties of Traditional Bulk Bread Covered with Probiotics and Soybean Oil Edible Coating
Probiotic food products are available at the supermarket commercially, but probiotic bakery products are much less in evidence. In the present study, methyl cellulose (2%), whey protein concentrate (2%), corn starch (1%), and soybean oil at 2, 4, and 6% were used for coating layer on the bulked bread surface, and then the quality properties were studied. The results showed that Lactobacillus rhamnosus GG, as probiotic component of the coating, immobilized in corn starch, whey protein, and methyl cellulose films had enhanced viability throughout shelf-life. The probiotics remained viable for 4 days, maintaining high viable cell number levels. Adding soybean oil at 6% concentration enhanced texture, sensory properties, and image index during storage
Socioeconomic determinants of unmet need for outpatient healthcare services in Iran: a national cross-sectional study
Background: Unmet need is a critical indicator of access to healthcare services. Despite concrete evidence about unmet need in Iran�s health system, no recent evidence of this negative outcome is available. This study aimed to measure the subjective unmet need (SUN), the factors associated with it and various reasons behind it in Iran. Methods: We used the data of 13,005 respondents over the age of 15 from the Iranian Utilization of Healthcare Services Survey in 2016. SUN was defined as citizens whose needs were not sought through formal healthcare services, while they did not show a history of self-medication. The reasons for SUN were categorized into availability, accessibility, responsibility and acceptability of the health system. The multivariable logistic regression was used to determine significant predictors of SUN and associated major reasons. Results: About 17 of the respondents (N = 2217) had unmet need for outpatient services. Nearly 40 of the respondents chose only accessibility, 4 selected only availability, 78 chose only responsibility, and 13 selected only acceptability as the main reasons for their unmet need. Higher outpatient needs was the only factor that significantly increased SUN, responsibility-related SUN and acceptability-related SUN. Low education was associated with higher SUN and responsibility-related SUN, while it could also reduce acceptability-related SUN. While SUN and responsibility-related SUN were prevalent among lower economic quintiles, having a complementary insurance was associated with decreased SUN and responsibility-related SUN. The people with basic insurance had lower chances to face with responsibility-related SUN, while employed individuals were at risk to experience SUN. Although the middle-aged group had higher odds to experience SUN, the responsibility-related SUN were prevalent among elderly, while higher age groups had significant chance to be exposed to acceptability-related SUN. Conclusion: It seems that Iran is still suffering from unmet need for outpatient services, most of which emerges from its health system performance. The majority of the unmet health needs could be addressed through improving financial as well as organizational policies. Special attention is needed to address the unmet need among individuals with poor health status. © 2021, The Author(s)
Geometric morphometric approach on the sexual dimorphism of Cydia pomonella (Lep.: Tortricidae) in the North West of Iran
In order to study the sexual dimorphism of codling moth, Cydia pomonella (L.), nine geographical populations were collected from four provinces, East Azarbayjan, West Azarbayjan, Ardebil and Zandjan, in the North West of Iran in autumn 2003. By transforming the landmark geometric data into partial warp scores, 26 and 18 scores were obtained for the fore and hind wings, respectively. Relative warp analysis was performed and wings relative variations in two sexes were determined. Allometry test was carried out after estimating centroid size of individuals. Population-sex interaction was significant in two wings. To determine the contribution of uniform and non-uniform shape variables in explaining populations and sexes differences, MANOVA was performed separately for each type of variables. The result revealed that the non-uniform variables were more effective in determining sex differences in different populations especially in the hind wing. Simple analysis of variance (ANOVA) indicated that the centroid size of females was significantly greater than that of males. Allometry test revealed non significant association between centroid size and wing shape variations in males and females. RWA showed well discrimination between sexes, especially based on the hind wing landmarks. Overall shape deformation indicated wider basal part of wing in females compared with males especially in the hind wing
Preparation of inactivated vaccine to induce resistance against white spot syndrome virus by nuclear & non nuclear techniques
The inactivated of white spot syndrome virus (WSSV) by Gama and Electron radiation and chemical material such as Formalin with antigen property have been done during last year. At the first time the stock of virus prepared and purred it. Six hundred of shrimp Fenneropenaus indicus with average weight 7 to 12 gram collected from shrimp research station in Heleh area and transported to Shrimp Research Institute in Boushehr province. Vibrio parahemolyticus obtained from Veterinary University of Tehran and then lyophilized it. The bacterial V. parahemolyticus inactivated with Gamma, electron and formalin and then injected to shrimp for activated the immune system. The source of viruses was identified through PCR, TEM and histopathology methods from the shrimp infected in 2009 occurrence of boushehr province. The virus injected to crayfish and collected the hemlymph for prepared the stock of WSSV virus. The virus was lyophilized and then exposed to gamma and electron radiation and formalin with optimal dose for inactivated the virus. The shrimp divided to 25 groups and each group consist of six shrimp and the vaccine exposed to shrimp with injected and bathroom methods and the documented the result after 15 days. In vivo virus titration was performed in Penaeus indicus. Inactivation of WSSV was carried out by a gamma cell instrument Nordian, model 220 with dose rate: 4.8 Gy/sec and activity: 20469 Ci. The LD50 of live virus stock was calculated 10 5.4 / ml and the optimum dose of gamma radiation beam to inactivate WSSV was obtained 14-15 kGy. The LD50 of live virus stock was calculated 10 5.4 / ml and the optimum dose of electron beam to inactivate WSSV was obtained 12-13 kGy and and the virus inactivated by formalin 0.5% V/V during 10 minutes.The LD50 of live virus stock was calculated by Karber method 10 3.29 /ml and 10 5.35 /ml, respectively. The V. parahemolyticus was inactivated with 8 KG. The result showed all vaccine during 2 hours have a good effect to shrimp viruses with the 102.4 LD50 / 50 l titre. The result showed if the Gamma and electron vaccine increase to feed of shrimp the effect of vaccine is better than when used without feed. The end of experiment our study showed that the Gamma vaccine has the better effect to control WSSV during 2 hours with comparing the others
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