Distribution of the Ratio of Normal and Rice Random Variables

The ratio of independent random variables arises in many applied problems. The distribution of the ratio |X/Y| is studied when X and Y are independent Normal and Rice random variables, respectively. Ratios of such random variables have extensive applications in the analysis of noises in communication systems. The exact forms of probability density function (PDF), cumulative distribution function (CDF) and the existing moments are derived in terms of several special functions. As a special case, the PDF and CDF of the ratio of independent standard Normal and Rayleigh random variables have been obtained. Tabulations of associated percentage points and a computer program for generating tabulations are also given

COMPARING THE GENERAL HEALTH, LIFE EXPECTANCY AND HAPPINESS OF MOTHERS OF AUTISTIC CHILDREN WITH MOTHERS OF NORMAL CHILDREN

This study compares life expectancy, public health and happiness of mothers of normal students with mothers of autistic children. Autism is a pervasive developmental disorder that is yet unknown as most serious and most childhood disorders. As long the incidence of autism is increasing, the focusing on the needs and experiences of parents is urgent. This study compared general health, happiness and hope to the lives of mothers of children normal with mothers of autistic children. Participants in the study were mothers of autistic and normal school students in Mazandaran Province, Iran. 112 mothers were selected through cloning method. Miller hopes questionnaire, a questionnaire with 28 questions GHO, Oxford Happiness Questionnaire used as research tools for statistical analysis of data, descriptive statistics (such as frequency tables, charts, etc.) and inferential statistics, independent t-test to compare two groups were used. The results showed that hope, health and happiness of mothers of autistic and normal students the difference was significant. The results showed that students' disabilities and autism has negative effects on their mothers' general health, hope, and happiness.  Article visualizations

Comparison of AH26 Physicochemical Properties with Two AH26/Antibiotic Combinations

INTRODUCTION: The purpose of this study was to compare the setting time and post-setting solubility, flow, film thickness and dimensional changes of AH26 root canal sealer with AH26-Antibiotic combination. MATERIALS AND METHODS: This study was performed according to British standard BS 6876 (2001) which tests the physicochemical properties of endodontic sealers. Three samples of each of tested materials including AH26 alone, AH26/amoxicillin and AH26/doxycycline were used to test each of the properties. They were prepared according to ISO protocols. RESULTS: The setting time of studied materials was 46 hours for AH26, 29 hours for AH26/amoxicillin, 49 hours for AH26/doxycycline. Flow test results were as follows, for AH 26, 15.6 mm; AH26/amoxicillin, 14.9 mm; AH26/doxycycline, 14.2 mm. Film thickness was 0.024 mm in AH26, 0.0283 mm in AH26/amoxicillin, 0.0276 mm AH26/doxycycline. The solubility of AH26 was 0.0076%, AH26/amoxicillin, 0.0113%, and for AH26/doxycycline, 0.013 %. Dimensional changes following setting was 0.07 mm, 2.6 mm, and 1.1 mm for AH 26, AH26/amoxicillin, and AH26/doxycycline, respectively. CONCLUSION: The physico-mechanical properties of AH26 antibiotic combinations were superior compared with AH26, with the exception of flow. Also, AH26/amoxicillin had a lower setting time than AH26. However, all values were within an acceptable range which conformed to ISO

The pore-level investigation of phenomena affecting the recovery of oil with gas assisted gravity drainage

Gas Assisted Gravity Drainage (GAGD) is an effective method of oil recovery that can be implemented injecting gas in the crest of reservoirs and producing oil from lower zones. GAGD is controlled by the interaction between capillary, gravitational and viscous forces, which depend on parameters of the operation, porous medium, and fluids. In this research, the performance of GAGD under various conditions was investigated by visualizing the flow of fluids at the pore-level to understand phenomena affecting the recovery of oil. A new pore network micromodel with an improved capillary continuity was developed that provides a transparent porous medium for studying the interplay between capillary, gravitational and viscous forces. The visualization of fluids’ interfaces helped with the characterization of GAGD performance under various conditions. Results of the studies imply that the porous medium heterogeneities caused the gas-front to bypass oil in smaller pores surrounded by larger pores. The bypassed oil could flow in the form of thick films in fine capillaries of porous media upon a subsequent enhancement of the gas-oil capillary pressure due to the effect of gravity on the gas-oil differential density. In the presence of mobile water, a better GAGD performance was obtained under oil-wet conditions as the hydraulic continuity of oil under water-wet conditions can be arrested by the residual water in small pores and fine capillaries of a porous medium. Although the recovery of oil at earlier times after a gas-breakthough was higher under oil-wet conditions, extending the duration of GAGD resulted in a high oil recovery under water-wet conditions upon an effective reduction of the residual water saturation. In post-waterflood GAGD, increasing the production rate resulted in the instability of the gas-front and the reduction of oil recovery at gas-breakthrough because of viscous pressure drops and capillary pressure associated with the flow of oil and water from trailing zones toward leading zones of the gas-front. Experimental results suggest that both oil-wet and water-wet reservoirs are excellent candidates for the implementation of post-waterflood GAGD. However, higher rate of oil drainage with less water production can be expected from early stages of the process in oil-wet reservoirs. Under water-wet conditions, although the production rate of oil is initially low, a very low residual oil saturation can be obtained after an effective reduction of the water saturation

Development of Probiotic Apple Juice using Encapsulated Probiotics in Xanthan-Chitosan Based Hydrogels

Background and Objective: Non-dairy probiotic beverages such as fruit juices have gained attention for consumption due to the presence of vitamins, minerals, antioxidants and bioactive components that are pleasant for all age groups and do not contain allergens such as milk proteins and lactose. To exert their health benefits, probiotics should survive during food processing and storage as well as gastrointestinal tract. Incorporation of probiotics into fruit juices is more complex than dairy products because of their low pH. In this regard, encapsulation of probiotics using various hydrocolloids and suitable methods can protect probiotics from detrimental factors and improve their viability. Material and Methods: In the present study, Lactobacillus plantarum and Bifidobacterium bifidum were incorporated into apple juice and the physicochemical properties of fruit juice (pH, acidity, °Brix and color), the viability of probiotics and sensory characteristics of apple juices were investigated during 60 days storage at 4°C. Results and Conclusion: The results showed that both bacteria survived in encapsulated form until the end of storage. Apple juices with free probiotics had lower pH, °Brix and higher acidity compared to encapsulated bacteria. Sensory evaluation of samples revealed that apple juices with encapsulated probiotics received higher scores than free bacteria. It can be concluded that using xanthan-chitosan hydrogels can be used for an efficient encapsulation of probiotics and improve their survival during storage without adverse effects on sensory propertie

A new hybrid algorithm for multi‐objective reactive power planning via facts devices and renewable wind resources

The power system planning problem considering system loss function, voltage profile function, the cost function of FACTS (flexible alternating current transmission system) devices, and stability function are investigated in this paper. With the growth of electronic technologies, FACTS devices have improved stability and more reliable planning in reactive power (RP) planning. In addition, in modern power systems, renewable resources have an inevitable effect on power system planning. Therefore, wind resources make a complicated problem of planning due to conflicting functions and non-linear constraints. This confliction is the stochastic nature of the cost, loss, and voltage functions that cannot be summarized in function. A multi-objective hybrid algorithm is proposed to solve this problem by considering the linear and non-linear constraints that combine particle swarm optimization (PSO) and the virus colony search (VCS). VCS is a new optimization method based on viruses’ search function to destroy host cells and cause the penetration of the best virus into a cell for reproduction. In the proposed model, the PSO is used to enhance local and global search. In addition, the non-dominated sort of the Pareto criterion is used to sort the data. The optimization results on different scenarios reveal that the combined method of the proposed hybrid algorithm can improve the parameters such as convergence time, index of voltage stability, and absolute magnitude of voltage deviation, and this method can reduce the total transmission line losses. In addition, the presence of wind resources has a positive effect on the mentioned issue

Partial harvesting from intensive shrimp (penaeusvannamei) culture pond in helle site

In this investigation, were examined the effect of partial harvesting on optimal management of shrimp culture. In order to achieve to the purpose 6Pool0.4/hectare was selected. Three pool with density Twenty-five per sq. m as a witness and another three pond by density fifty per sq. m as the test sample were storage. Based on the results of biometry and biomass estimates of pool was calculated and provided amounts daily meals for shrimps. The first harvest took place after a period of120 days from the test pools .Average of harvest from pools B4, B6 and B7, was determined respectively, 1373,1365 and 1105kg. Second harvest from treatment poolsB4, B6andB7were determined, respectively, 1663, 1748 and1783kg. Final harvests from the pools were after 150 day. Harvest average from control pools B1, B2 and B3 was calculated and estimated respectively, 1824, 2000 and 1685 kg. The Average of FCR was calculated 1.51 in control samples. In general, the average of feed conversion rate of the treatment samples were calculated 1.51.We did not see the difference between FCR of control and test samples. According to the project's achievements, we can say, partial harvesting has an important role to increased productivity of shrimp farms in Helleh site from Bushehr Province

Estimation of MSY on six species of commercially important demersal fishes in the Persian Gulf & Oman Sea (Hormuzgan province)

Today, calculation of MSY is one of the necessary fisheries management in control and prevention of the fish population reduction and is obtained with different methods. This study has focused on six species of commercial fish, including Tiger-toothed croaker, Javelin grunter, John`s snapper, Indian spiny turbot, Yellowfin seabream and Silver pomfret. The study was done monthly, from January 2007 to March 2008, in three fish landing regions including: Bandar Lengeh, Bandar Abbas and Qeshm Island (Slakh, Basydu and Chahoshrqy). Total 5163 Silver pomfret (Pompus argenteus), 1766 Javelin grunter (Pomadasys kaakan), 2151 John`s snapper (Lutjanus johnii), 3280 Tiger-toothed croaker (Otolithes ruber), 1628 Indian spiny turbot (Psettodes erumei) and the number of 759 Yellowfin seabream (Acnthopagrus latus) were assessed and length biometry has been done, monthly. In this study, two methods were used to determine the maximum sustainable yield (MSY): 1- virtual population analysis (Cohort analysis) 2- use of statistics and information that was estimated with two method, catch prediction and biomass (Standing stock). The results showed that in 2007, MSY value was estimated through catch prediction for Silver pomfret, Tigertoothed croaker, Javelin grunter, John`s snapper, Indian spiny turbot and Yellowfin seabream 1354, 1116, 1099.6, 1045.5, 914.5 and 529.5 tons, respectively. Moreover, this estimation have been done through standing stock for Silver pomfret, Tiger-toothed croaker, Javelin grunter, John`s snapper, Indian spiny turbot and Yellowfin seabream 1215, 633, 1304, 878, 1095 and 441 tons, respectively; and through VPA for Silver pomfret, Tiger-toothed croaker, Javelin grunter, John`s snapper, Indian spiny turbot and Yellowfin seabream 1100, 850, 920, 732.5, 1002.3 and 403 tons, respectively. Amount of biomass (Standing Stock) was estimated for Silver pomfret, Tiger-toothed croaker, Javelin grunter, John`s snapper, Indian spiny turbot and Yellowfin seabream 2530, 1172, 1738, 1689, 1470 and 1110 tons, respectively. In general, by assessing the obtained results for the studied species, except the fishing prediction results of the Javelin grunter and Tiger-toothed croaker species, which is less valuable due to the low correlation coefficient, it can be stated that except fishing pressure on John`s snapper and Tiger-toothed croaker, in other species studied, fishing conditions are in optimal situation

Determination of sustainable exploitation level of Penaeus semisulcatus in Bushehr province water

This study was carried out in Bushehr province waters (49ْ 40"E and 30ْ 00"N to 52ْ 00"E and 27ْ 40"N) in July and August 2010-2011. The objectives of this study were to determine the opening and closure periods of shrimp and to estimate of the shrimp biomass in the study area. Based on the total length, the opening season of shrimp fishery in 2010 and 2011 were proposed on 12 and 22rd of July, respectively. The closed season was determined based on the remaining of 20% of shrimp stock and proposed on 12 and 29th of August, respectively. The primary estimation of the biomass in these years was 840 and 455 metric tons, respectively. While the total catch were estimated 847 and 859 tones in these years. During this study 9 species of the penaeid and solenoserid species were identified. The percentage of the green tiger prawn to the other species in the study years were 73% and 92%, respectively

Monitoring green tiger prawn stock in Bushehr Province waters

The results of 30 months of trawl sampling on P. semisulcatus, De Hann 1848, obtained through operational phase of MONITORING GREEN TIGER PRAWN RESOURCES project, along with results of another available 28 months of the data of the same structure prior to this, has formed an invaluable time series of data as a proper basis for the further analysis. The survey area is located at North-west of the Persian Gulf from Bahrekan to Dayer waters. The ultimate goal of this study is to come to a better understanding of behavioral pattern of Green Tiger Prawn in its exploited phase after recruitment to the fishery. In this study, the confirmation of the life cycle of P. semisulcatus, to the general life pattern of Penaeidae shrimps was observed. Of the peculiarities of this pattern are the yearly bi-modal spawning and two corresponding peaks of recruitment. There exist two spring and autumn generations, which the major spawning in autumn produces the main recruitment in summer and the autumn generations stem from spring spawning. The spatial and temporal distribution of shrimp is highly variable by month and year. Depending on the year, higher shrimp densities are often found in early summer between Lavar and Rostami and/or Rostami to Bushehr and extend north and south in August. This result can be used in better design of sampling scheme for nursery studies. The main recruitment, which the fishery is depended upon, is in July to August and a second one occurs December-February. The timing and strength of both recruitments vary inter-annually. The proportion of prerecruits in southern area is always higher and the modes more prolonged than in northern area. The period of major recruitment starts earlier and lasts longer in the south than the north. A consistent pattern is not seen for the secondary recruitment, which, usually occurs in December-January. It is hypothesized that 1- the secondary recruitment might occur in Kuwait and/or Saudi Arabia waters, 2- insufficient number of spawners in spring or 3- high mortality in summer could cause the weakness of secondary recruitment. The spatial distribution of the mature female shrimps in spawning months indicates that the northern part of study area is an aggregation ground. It is also found that this aggregation grounds are close to two main fresh water sources (Helleh and Mond rivers), and these phenomena can be somehow related. The average length at 50% maturity varies inter- annually and is estimated to be 15.3 Cm. Length-frequency distribution of shrimps by sex reveals 1 to 3 modes depending on the month and year. In southern part a more complicated and less consistent pattern of recruitment and growth between years was observed. There is multiple or/and continuous recruitment especially during summer months. The von Bertalanffy growth parameters were estimated. The Findings are used to design new sampling schemes to cover the whole life cycle of this species enabling one to explain the variations in their response to the environment and fishery. The results of this study, lead us in building appropriate assessment and management models