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McGurk effect is a perceptual phenomenon in which subjects use information from both auditory and visual modalities to come into a unified percept. In the classic example of McGurk, when auditory /bɑ/ is dubbed over the lip movements of /ɡɑ/ , subjects report perceiving /da/. Although this illusion is not considered a universal one, it is experienced by the majority of subjects. The effect had been the subject of multiple studies in different languages. The present study is the first survey which examines this effect in Persian and Kermanshahi Kurdish language. Our main question is to examine whether the effect is significant in Persian and Kermanshahi Kurdish language. We also investigated the effect of gender on the occurrence of this phenomenon. It investigated McGurk in Persian and Kermanshahi Kurdish subjects. 121 (11*11) audiovisual stimuli were presented to 120 subjects (60 Persian speakers and 60 Kermanshahi Kurdish speakers). The Results demonstrate a reduced McGurk effect in both Persian and Kermanshahi Kurdish subjects; however, the probability of its occurrence is significant in Kermanshahi Kurdish. The phenomenon is highly significant when an auditory labial CV is dubbed with a visual velar CV for Persian subjects; however, for Kermanshahi Kurdish subjects the effect was robust when an auditory velar CV is dubbed with a visual palatal CV. The effect of gender (both presenter and subjects) on the occurrence of this effect is also studied in this research. Results show significant effect of gender on audio-visual perception of consonants. However, if the percept happens, female presenters significantly affect the audio-visual perception of the subjects.                     
 

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Pseudomonas tolaasii Paine and Ewingella americana Grimont are considered as devastating pathogens in mushroom cultivation. Due to the short shelf life of button mushrooms, safe methods should be used to control these pathogens to avoid any toxic residues on the products. Plant secondary metabolites are assumed as important sources for biopesticides development. The aim of this study was to screen plant species for antibacterial properties against P. tolaasii and E. americana. Antibacterial activity of aqueous extract of 17 plant species on two pathogens was investigated in vitro using the disc diffusion method at 10 and 20 mg active ingredients per disc. Then the effect of extracts possessing antibacterial activity was tested on mycelial growth of button mushroom Agaricus bisporus (Lange) using the disc diffusion method. Analysis through measuring the diameter of growth inhibition zones revealed that the extract of Hymenocrater longiflorus Benth. and the other extracts including H. longiflorus, Achillea millefolium L., Eucalyptus sp. and Teucrium polium L. had significant antibacterial activity on E. americana and P. tolaasii, respectively. However, they had no inhibitory activity on mycelial growth of A. bisporus. The efficacy of four mentioned extracts was evaluated in the control of mushroom brown blotch disease caused by P. tolaasii, in vivo. Assessment of disease severity showed that all four extracts, at tested concentrations, had some level of preventive effect on P. tolaasii with no adverse effects on A. bisporus. It is noteworthy that the strength of the A. millefolium extract at 10% did not differ significantly from the 1% household bleach in reducing the disease severity. Therefore, it is possible that some plant extracts have the power to be considered as alternatives to chemical bleaches. Moreover, findings suggest that H. longiflorus extract is a promising candidate for control of P. tolaasii and E. americana in mushroom cultivation.

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Introduction:
Fricatives not only differ in their acoustic structures from one language to another, but also they vary considerably from individual to individual. Acoustic correlates of fricatives are sensitive to the shape and size of the resonance cavity in front of the oral constriction. It is therefore conceivable that any physical change in the length and place of constriction during production of fricatives may alter the resultant acoustic signals. This research attempts to explore potential speaker-specific acoustic parameters of voiceless fricatives in Persian based on experimental phonetics. Therefore, acoustic parameters of center of gravity and fricative duration are investigated for each voiceless fricative in Persian. This research aims to discover whether voiceless fricatives and selected acoustic parameters are able to discriminate between speakers in Persian and whether these fricatives and acoustic parameters are of assistance in segregating speakers in Persian. According to the aforementioned considerations, the following questions are presented in this paper:

1. Do the selected acoustic parameters (center of gravity and duration) of voiceless fricatives have capacity to differentiate speakers in Persian?
2. Which acoustic parameters and which voiceless fricatives discriminate Persian speakers the best?

 Furthermore, we will compare the results of the present study to the findings of previous studies to see in what way Persian has been similar or different from other investigated languages.
Methodology:
In order to analyze between- and within speaker variability of voiceless fricatives, 24 Persian speakers (12 male, 12 female) on two separate occasions were recorded in the sound proof booth at phonetics laboratory of Alzahra University. Non-contemporaneous recording of speech material allows us to measure the degree of within-speaker variability across each speaker. The speech material consists of a read passage which contains 54 Persian sentences including relevant voiceless fricatives Speech tokens were acoustically measured with PRAAT version 5.2.34 and statistical analyses were carried out with SPSS version 21 and R version 3.3.3.
Results and conclusions:
Results of this study indicated that for female speakers, center of gravity of /S/ and s/  have the best performance in showing between-speaker variability. For male speakers, center of gravity of /s/ is the most highly discriminant acoustic parameters across speakers. Moreover, fricative duration was not reported as a promising acoustic parameter. Center of gravity is directly linked to the size and length of the vocal tract. The longer is the length of the vocal tract, the higher is the center of gravity and vice versa. This indicates that anatomical differences between speaker’s vocal tract influence the acoustic properties of fricatives and ultimately make them distinctive. In the future studies, additional parametric potential speaker-specific features will be examined in order to determine a set of well-established discriminant parameters for voiceless fricatives in Persian.
 

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Abstract
Aims: Pronation distortion syndrome (PDS) is a common postural deviation that can lead to various complications. Prevention and reducing the risk of injury are more important than treatment, and a significant part of this issue can be achieved through pre-participation screening. This study aimed to compare the functional movement screening (FMS) scores in female athletes with and without PDS.
Methods: This study included female athletes with and without PDS, divided into PDS (N=20) and WPDS groups (N=20). PDS was assessed with navicular drop index for flatfoot, flexible ruler for lumbar lordosis, and caliper for Genu valgum, respectively.  The FMS kit was used to determine the FMS scores. The independent T-test was used to analyze inferential statistics, and the Mann-Whitney U test was used to analyze non-parametric data. The significant level is considered to be p < 0.05.
Findings: The results showed significant differences in deep squat (P<0.001), hurdle step (P<0.007), in-line lunge (P<0.027), active straight leg raise (P<0.006), trunk stability push-up (P<0.011), and rotary stability (P<0.005), indicating that the scores for these items were higher in WPDS compared to PDS. Additionally, the findings suggested no difference in shoulder mobility (P<0.277) between the two groups.
Conclusion: PDS seems to influence different body parts' musculoskeletal and functional status, resulting in lower FMS scores among female athletes with PDS. Routine screening and targeted corrective strategies should be implemented to enhance movement quality and decrease injury risk within this group.
 

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Voicing is one of the most important phonological features in distinguishing consonants in many languages. In this study, we investigated the temporal parameters such as constriction duration, voice duration, and vowel duration in stop and fricative consonants of Azeri Turkish language in intervocalic position (VCV). The main purpose of this study is to study stop and fricative consonants in Tabrizi dialect. An attempt was made to answer the question of how the voicing of stop and fricative consonants of Turkish language affects the temporal parameters. Twelve selected words of Turkish common words were repeated by fourteen Tabrizi speakers. They were produced three times in citation form. The results showed that temporal parameters are considered as potential cues in distinguishing voiced and voiceless Turkish consonants. The results related to stop consonants also showed that only voice duration and vowel duration were effective in the voicing contrast. The results for the closure duration confirmed that there is no significant difference between voiced and voiceless stops and this cue can not be used as a distinguishing cue to voicing in Azeri Turkish stops.

1. Introduction
Glottis and its condition is one aspect of describing consonants; So the vibration in vocal cords during consonant production produces voiced sounds unless the produced sound is voiceless. Voicing is one of the phonological features that has been discussed in most languages ​​and has certain acoustic cues. Some of these cues are defined as temporal features, which include constriction duration, voice duration, and the preceding vowel duration. In other words, these temporal features are considered cues for distinguishing obstruent consonants. Steriade (1997, pp. 6-7) offers a list of cues to voicing and their distribution and believes that changing stop consonants’ position in a syllable can cause a change in the number of voicing cues. closure duration and closure voicing are two essential cues to study stop consonants voicing. Moreover, there are sixteen acoustic features classified into three groups including pre-closure, closure, and post-closure features (Lisker, 1986). Lisker (1986) argues that these features are potentially perceptual cues to voicing distinction in the intervocalic position. This means that closure duration and voice duration are associated with closure, and vowel duration relates to pre-closure features.
Turkish language is one of the most common languages in the Altaic language family which has the largest number of speakers (Crystal, 1987, p. 307). The southwestern branch is one of the main branches of Turkish language, which includes Azerbaijani, Turkish, and Turkmen (Hayat, 2001, p. 8). In general, the Turkish language of Azerbaijan can be divided into two dialects: the northern dialect in the Republic of Azerbaijan and the southern dialect in Iranian Azerbaijan (Johanson, 1998). Among the common non-Persian languages ​​in Iran, Azerbaijani Turkish with 15 to 20 million native speakers has the highest number of speakers (Crystal, 2010) and also among 26 types of Azeri dialects, Baku, Guba, Lankaran, Shirvan, and Tabrizi dialects are common in East Azarbaijan region (Heyat, 2001). This language is agglutinative ​​and has 24 consonants and 9 vowels. Vowels are /ɑ, ɯ, o, u, æ, e, i , œ, y/. Also out of 24 consonants, there are 6 stop consonants / b, p, d, t, ɡ, ɟ / and 9 fricative consonants /f, v, s, z, ʃ, ʒ, x, ɣ, h/ in this language. Additionally, there are two other stops /c/ and /k/ that are used only in the Southern dialect and in loan words (Ghaffarvand Mokri and Warner, 1396).
The main purpose of this study is to examine stop and fricative consonants of Azeri Turkish in the Tabrizi dialect, acoustically. So that these consonants will be evaluated by measuring acoustic cues such as closure duration, voice duration, and vowel duration in intervocalic position. This is an experimental study that will be performed by designing a production test. In this study, we aim at providing an answer to the following question: whether voicing has a significant effect on the duration of acoustic cues in stop and fricative consonants in Azeri Turkish language? We assume that the duration of above-mentioned cues is significantly influenced by voicing feature of obstruents.

2. Literature Review
There are several studies done on many languages evaluating acoustic cues in obstruent consonants such as stop closure duration (Shen et al., 1987; Lisker, 1957; Nikrahi, 2012; Razavi Najafabadi & Nourbakhsh, 2013), fricative constriction duration (Jongman, 2000; Nartey, 1982; Klatt, 1976; Baum &Blumstein, 1987; Rahimi, 2013), affricate closure and frication duration (Hosseinpoor Damirchan & Nourbahsh, 2021), voice onset time (Jahan, 2009; Ünal-Lugacev et al, 2018) and vowel duration ( Ladefoged, 2006, p. 58; Chen, 1970; Raphael, 1972; Warren & Marselen-Wilson, 1989).

3. Methodology
Fourteen Azeri native speakers participated in the production experiment. Twelve Turkish words containing 4 stops /d, t, b, p/ and 8 fricatives /z, s, ʒ, ʃ, ɣ, x, v, f/ were produced in the intervocalic position between vowels /ɑ/. Participants were in a quiet room and produced syllables three times in citation form and also they were asked to repeat with a short interval between each word. Thus, 504 data were obtained (14 speakers × 12 words × 3 repetitions). Praat voice Analysis Software Version 6 .1. 30 were used for acoustic analysis of data. All measurements were done manually considering both waveforms and spectrograms. Also, SPSS software Version 23 was employed for statistical analysis.

4. Results
4-1. Stop closure duration and Frication duration
Closure duration in stop consonants provides two main acoustic information associated with the voicing feature. Examining this cue showed that the length of closure is not significantly longer in viceless stops than voiced (p ≥0.05). The mean closure duration is 93.87 and 98.86 for voiced and voiceless stops respectively. Therefore, closure duration can not be considered a proper acoustic cue to contrast voicing in Azeri Turkish stops.
The results of frication length measurement showed that voiceless fricatives (mean duration: 161.7) are longer than voiced fricatives (mean duration: 91.58). Mean and standard deviation are shown in table 2 for each fricative. The longer duration of voiceless fricatives is significant (p ≤ 0.05) and leads to the result that length of frication is an important cue to fricatives voicing. Table 1 shows descriptive statistics of stops closure duration and fricative constriction duration.

Table 1.
 Descriptive statistics of constriction duration in stops and fricatives

		Mean	SD	Min	Max
Stop	voiced	93.87	16.88	58	145
	voiceless	98.86	23.26	48	148
fricatives	voiced	91.58	24.38	50	166
	voiceless	161.7	25.54	104	218

4-2. Stop and fricative voice duration
Mean and standard deviation are shown in table 2 for stop and fricative consonants. The average voice duration obtained for voiced stops is 57.79 which is longer than voice length in voiceless stops with 25.13, therefore the significant difference between voiced and voiceless stops (p ≤ 0.05) demonstrates that voice length is the main cue to voicing recognition.
The overall average voice duration for voiced fricatives is longer than the voiceless with 86.33 and 29.93 respectively. In other words, voiceless fricatives have shorter voice length and this difference is considerably significant (p ≤ 0.05). Thus, voice duration is considered an important cue to voicing category of fricatives.

Table 2.
 Descriptive statistics of voice duration in stops and fricatives

		Mean	SD	Min	Max
Stop	voiced	57.79	27.37	10	112
	voiceless	25.13	11.45	7	63
fricatives	voiced	86.33	26.32	17	166
	voiceless	29.93	10.89	10	80

4-3. Vowel duration preceding stops and fricatives
Mean and standard deviation of vowel length before stops and fricatives are shown in table 3 and indicate that length of vowel before voiced consonants are longer than voiceless ones. The significant difference of voiced and voiceless stops and fricatives (p ≤ 0.05) shows that the duration of vowel precesing obstruens is an essential cue to the voicing distinction.
Table 3
 Descriptive statistics of vowel duration before stops and fricatives

		Mean	SD	Min	Max
Stop	voiced	114.87	23.43	60	184
	voiceless	96.94	23.02	59	170
fricatives	voiced	135.74	32.34	76	234
	voiceless	101.33	23.11	53	159

6. Conclusion
In this study, three acoustic cues in stop and fricative consonants voicing were investigated for speech production in Azeri Turkish language spoken in Tabriz. Except for stop closure duration, the other cues showed significant differences between voiced and voiceless obstruents. Hence, frication duration, voice duration, and vowel duration before obstruents are potential cues to voicing distinction in Turkish language in Tabrizi dialect.

 

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Friction stir process is one of the severe plastic deformation techniques which causes microstructure refinement and hence change in mechanical properties of the specimen. Temperature, strain and strain rate which are the results of this process, causing dynamic recrystallization and followed by shift in mechanical properties. Magnesium is the lightest structural alloy which is used in a wide range, in the automobile and aerospace industries. In this research, the overlapping friction stir process is applied on the surface of AZ31 alloy. The overlapping is conducted in 50 and 0 percentages. In order to reduce the temperature which is generated in the process, rapid cooling was used. After friction stir processing in the 0 percent overlapping the grains refine from 18 micrometer in the base metal to 7 micrometer with a uniformer structure than the base metal, ultimate tensile strength and elongation increased 29.9% and 19.8%, respectively with respect to the base metal. The structural uniformity of 50 percent overlapping was less than that of 0 percent overlapping, ultimate tensile strength and elongation increased 19.98% and 3.9%, respectively with respect to the base metal.

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Nowadays, using renewable energies, specifically ocean wave energy, is of importance in the world. One of the methods by which this energy can be harnessed is through using axial turbines with low head. In this study, performance of an axial turbine ocean wave of Wells type installed on the floating oscillating platform has been numerically studied. The length of the oscillating bed is equal to the wave length of the ocean upon its center the Wells turbine has been installed. This design causes the inlet flow rate to be doubled, which will in turn increase the power. In this way, the governing equations include continuity and momentum equations have been solved considering SST turbulence model. Furthermore, the acquired results have been verified through mesh independency analysis and have been validated by comparison with the available experimental data. The results show that with decreasing the clearance and setting it to 2% of the chord length value, the maximum efficiency, which is approximately 35%, will be gained. Moreover, by varying the angles from 0 to 12° with respect to its tip, achieve higher efficiency in different velocity ratios. On the other hand, employing a blade with variable profile will lead to postponing stall phenomena. Moreover, employing multistage turbines with guide vanes at the mid stage can improve efficiency by 9 percent.

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In this paper, by using the Armstrong- Frederick nonlinear kinematic hardening model, the ratchetting behavior of carbon steel piping elbows is described under conditions of steady internal pressure and dynamic moments out-of-plane at frequencies typical of seismic excitations. The elbows had an outside diameter of 60.3 mm and thicknesses of 3.91 and 5.54 mm. For each thickness two bend radius geometries (long and short) were studied. A pure out-of-plane bending moment applied at one end of a 90 welding elbow is reacted by a purely torsional moment at the other end. Three-dimensional elastic-plastic analyses by Armstrong-Frederick nonlinear kinematic hardening model are carried out to evaluate structural ratcheting behaviors. Initial, the rate of ratchetting is large and then it decreases with the increasing cycles. While there is practically no strain accumulation in the axial direction, the direction of highest ratcheting is along the hoop direction. The cyclic strain accumulation against response moment for each component is assessed. By Armstrong-Frederick model, the predicted ratchetting of low moments near is to the experimental results, while for the high moment, this model will over-predict the ratcheting strain.

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slip factor is one of the most important parameters used in centrifugal pumps performance prediction. Knowing this parameter as a function of flow rate seems essential for off-design performance prediction. In this paper, it is intended to establish the slip factor dependence upon flow rate for a centrifugal pump using computational fluid dynamics. For this purpose, the full 3D-RANS equations in coupled with RNG k-ε turbulence model were solved for several flow rates ranging from 45% to 120% of rated condition by means of a commercial code, CFX. In the steady state, this simulation is defined by means of the multi-reference frame technique, in which the impeller is situated in the rotating reference frame, and the volute is in the fixed reference frame. The validity of the numerical model was confirmed by matching the calculated characteristic curves with the associated experimental data. It was found that there is a good coincidence between the numerical results and available experimental data of global performance, local velocity distribution and slip factors. A comparison was performed among the well-known slip models which reveals, that the slip factor variations can be predicted very well using CFD analysis.

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One of the dysarthria features is inaccurate articulation of consonants and vowels, which is the main cause of speech unintelligibility. However, it is not clear what acoustic measures are more related to speech intelligibility in dysarthria. On the other hand, the number of vowels, their articulation and acoustic characteristics are various in different languages. As far as we know, no study investigated vowels articulation in developmental dysarthria in Persian, so there is not enough information about movement details which make their inaccuracies articulation. Hence, the present study aimed to investigate some acoustic measures including vowel formants, vowel space area (VSA), formant centralization ratio (FCR) and vowel articulation index (VAI) and aim to study their correlation with speech intelligibility in Persian speaking children with dysarthria due to spastic cerebral palsy. In this cross ـ sectional study, 11 monolingual children with dysarthria aged 3 ـ 9 years and their typically developing matched peers were selected through convenience sampling. For each of the six Persian vowels, two monosyllable words were acoustically analyzed using PRAAT software. To determine intelligibility of words and vowels, the percentage of correct detected ones was calculated. Results showed a significant difference between the two groups in the third formant of the vowels /a/ and /u/ and the second formant of the vowel /o/. The vowel space area and intelligibility were significantly reduced in dysarthria. VAS was more correlated with intelligibility and is a good acoustic measurement to assess speech intelligibility in dysarthria. However all three studied acoustic indices had moderate significant correlation with intelligibility.

1. Introduction
Abnormalities in power, speed, range, muscle tone, stability, and accuracy of movements necessary for respiration, phonation, production, articulation, or prosodic aspects of speech lead to dysarthria (Duffy, 2019). Depending on the location of the damage in the nervous system, there are different types of dysarthria and each creates different speech characteristics (Duffy, 2019). Cerebral palsy is one of the main causes of dysarthria in children. One of the main and distinctive features of dysarthria is imprecise production, which is the main factor for low speech intelligibility (De Bodt et al., 2002). However, there is limited information on the motor features that cause this inaccuracy in children’s production, and awareness of these motor events is a prerequisite for providing appropriate therapeutic approaches (Allison et al., 2017). If we consider syllables as speech motor units (Yunusova et al., 2008) and vowels as the core components of syllables, vowel distortion can affect the structure of syllables and consequently speech. Describing the vowels of a language has more auditory aspects than articulatory ones. However, gradually linguistics realized that if the vowels of a language are displayed based on F1 and F2 features, the result will be a two-dimensional space that they named vowel space. Since speech intelligibility is the primary goal of clinical interventions, and since vowels are a good predictor of speech intelligibility in dysarthria, it is necessary to accurately determine the correctness and accuracy of vowels with the help of appropriate diagnostic or perceptual tools to assess the effects of direct and indirect therapies on the proper production of vowels and the improvement of speech intelligibility. This diagnosis guides therapists in selecting appropriate treatment methods or continuing therapy.
Research Question(s)
Is the formant of each of the 6 vowels in Persian-speaking children with spastic dysarthria different from that of typically developing children? Are speech intelligibility, acoustic parameters of vowel space, vowel production indices, and formant centralization ratio different in children with dysarthria based on age? Is there a correlation between some acoustic parameters of vowels and speech intelligibility?


2. Literature Review
In 2019, a study was conducted in China on the Mandarin language with the aim of determining acoustic parameters for speech evaluation in children with dysarthria due to cerebral palsy. Thirty children aged 5 to 15 with cerebral palsy and 13 typically developing children participated in the study. Formants F1 and F2 were calculated for vowels /a, i, u/. The VSA, VAI, and FCR indices were also calculated and analyzed. In children with cerebral palsy, there were significant differences in F1 and F2 for the vowel /a/ and F2 for the vowel /i/, while there were no significant differences in F1 and F2 for the vowel /u/ and F1 for the vowel /i/. There were significant differences between the two groups in the FCR, VAI, and VSA indices (Mou et al., 2019). In another study in 2017 aimed at improving the understanding of speech characteristics related to dysarthria in English-speaking children with cerebral palsy in the United States, formants were analyzed at the word and sentence levels. The speech of 10 children with dysarthria due to cerebral palsy was compared to 10 typically developing children. The results showed that children with dysarthria had a smaller vowel space compared to typically developing children at both the word and sentence levels (Allison et al., 2017). The same researchers conducted another study in 2018 with the aim of determining acoustic characteristics of connected speech in children with dysarthria due to cerebral palsy and typically developing children. Twenty children with dysarthria were matched with typically developing children in terms of age and gender. The results showed that children with dysarthria differ from typically developing children in terms of speech-segmental and suprasegmental features (Allison & Hustad, 2018). In 2016, a study titled “Vowel Intelligibility in Children with or without Dysarthria” was conducted. Researchers in this exploratory study examined the vowel intelligibility of American English vowels in American children. Generally, children with dysarthria had lower vowel intelligibility compared to typically developing children, but there was no statistically significant difference in intelligibility among different vowels. These studies highlight the significance of focusing on the vowel system during therapy to enhance intelligibility (Levy et al., 2016).

3. Methodology
In the present cross-sectional study, 11 children with spastic dysarthria due to cerebral palsy were selected from rehabilitation clinics in Semnan city, and 11 typically developing age- and gender-matched children from preschools and primary schools in the same city. The inclusion criteria for children with cerebral palsy in the study were mild to moderate dysarthria due to spastic cerebral palsy, aged 3 to 9 years, and the ability to produce single words. Exclusion criteria were the presence of sensory or motor problems, bilingualism, dysphagia, and difficulties in producing consonants present in test words. Initially, 12 monosyllabic words with a CVC structure including 2 words for each of the 6 vowels in the Persian language were selected by a linguist and a speech-language pathologist, which were simple to produce in terms of consonants and did not affect the central vowel. Each word was uttered twice, so 4 words were spoken for each vowel, with 3 of them selected for formant analysis using PRAAT software. Subsequently, the spoken words by each child were presented to adults unfamiliar with the child, who were free of hearing or language issues, to write down the words after hearing them. The researchers determined the number of correct words and the vowels identified by adults to establish the percentage of vowel and speech intelligibility for each child. Finally, the two groups of children were compared in terms of vowel space and speech intelligibility.

4. Results
In this study, each group of children with normal speech and dysarthria included 4 girls and 7 boys with a minimum age of 3.5 and a maximum age of 9 years. The mean age in children with dysarthria was 1.9 ± 5.6 years and in the group with normal speech was 1.8 ± 5.7 years, with no significant difference between them (p > 0.05). Since results in speech production change with age due to vocal tract lengthening and children’s motor skill development, the children in this study were categorized into 2 subgroups of 3.6 to 6 years and 6 to 9 years. Comparison of vowels in children with dysarthria and their age-matched typically developing peers using the Mann-Whitney test showed a significant difference between the two groups only in 6 to 9-year-old children in the first formant of /i/ and /æ/ vowels, the second formant of /æ/ vowel, and also the third formant of /e/ and /a/ vowels. Speech intelligibility at the single-word and vowel level, acoustic parameters of vowel space, vowel production indices, and formant centralization ratio were compared between the two groups of children with dysarthria at different ages using the Mann-Whitney test, which showed a significant difference in word and vowel intelligibility between the two groups. All acoustic indices also showed a significant difference between the two groups. Vowel space, calculated based on the /a/, /i/, and /u/ side vowels in this study, was smaller in the group of children with dysarthria compared to the normal group. In both age groups, the dispersion of vowel production in the dysarthric group was higher compared to the normal children. The results of the Spearman correlation coefficient test showed a significant moderate relationship between all indices of vowels and speech intelligibility. This relationship was direct for the Vowel Space Area (VSA) and Vowel Articulatory Index (VAI) and inverse for the Formant Centralization Ratio (FCR).
 

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Strain accumulation of the components in power-plants and large industries, which causes physical and human costs, has been interested of many researchers in last decades, because of unexpected collapse of these components under periodic loads and internal pressure. In this study, the effect of four basic factors of piping elbow material, frequency of periodic loading (typically below 10 Hz), internal pressure of pipe and periodic dynamic moments on the amount strains accumulation of piping elbows have been considered. Also, the effect of factors variation listed above, on the amount of strains accumulation has been studied. Analyses done in this study, shows that increase in loading frequency, internal pressure and dynamic moments at the end of piping elbow, increases the amount of strains accumulation. Behavior of strain accumulation of two kinds of materials (carbon steel and stainless steel) was investigated in same condition. Studies showed that the strain accumulation in carbon steel are more than stainless steel due to differences in hardness behavior of these materials. The results showed that, stainless steel piping elbow has better performance compared to carbon steel.

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Pumps consume about 20% of whole electricity power in the world. Centrifugal pump is one of the most common pumps that works by the transfer of angular momentum to the fluid. The behavior of such a fluid flow in the side chamber, may affect the pump performance. The side chamber is defined the free space between the fixed (pump casing) and the rotating (pump impeller) parts. Steady, fully 3D computations of the Reynolds-averaged Navier-Stokes equations using a commercial CFD code are conducted in order to study the flow field in the whole pump including both side chambers. Numerical results are validated by comparison with the existing experiments. The impact of fluid flow in hub and shroud side chambers with the volute is investigated qualitatively by using 2D stream lines. Evaluation of the empirical equations shows that the frictional torque may be decreased more than 10%, by using the proper gap size. Considering this situation, the changes in the flow pattern and the value of power loss resulting from friction in hub and shroud side chamber is studied. It reveals that the variation in friction depends on the initial flow pattern in cavity. Finally, in order to obtain the relationship between the power loss and the flow rate, nondimensional coefficients are derived. These coefficients show that the change in the power loss due to the volumetric flow rate, is the same as its change with the gap changing, but their slopes are not equal.

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Manufacturing in as short time as possible, with highest quality and at minimal cost, is one of the key factors in industry. As a result, researchers are seeking new methods and technologies to meet such requirements. Liquid impact forming is one of such methods which has received wide currency especially in automotive and aerospace industries. In this method, which is considered as one of tubular hydroforming processes, forming is achieved by using liquid pressure. In this paper, liquid impact forming process was investigated experimentally and numerically for a thin-walled aluminium tube. In experimental part, a die was designed and manufactured to transform the cross section of the aluminium tube into a polygon which at the end of the process changes the cylindrical shape of the tube to a profile almost similar to a trapezoid. Results showed that a die in the form of matrix molding is not suitable for this type of geometry in such a process while using another die which consisted of three parts resulted in a satisfactory forming. Simulation of this process was further implemented using finite element method and results relating to Von Mises stress distribution, displacement, strain energy, internal energy, thickness variation and the force required to implement the process were obtained. Displacement distribution in different regions indicated that no wrinkling occurred in the sample. Comparison between simulation and experimental results indicated that they were in good agreement.

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Despite significant improved survival rate in patient with heart failure by Ventricular Assist Devices (VADs), complications related to blood hemolysis and pump thrombosis have challenged the improvement of these devices. Hence, the first step of VADs improvement is studding the flow field and the effect of different parameters on blood hemolysis. Consequently, at the first step of the current study, the CFD analysis of hemolysis in laminar flow inside a pipe and turbulent flow inside a chamber with rotating disc were compared with Analytical solution and experimental results, respectively, and good agreements were achieved. Then, numerical simulation was used to calculate the hemodynamics in one axial and one centrifugal pump as a Left Ventricular Assist Device (LVAD), and a comparative analysis of operating conditions, efficiency and hemolysis index was performed among them. The results showed that the axial VAD had a higher hemolysis index, due to its longer residence time and higher shear stress. The higher shear stress in simulated axial VAD compared to centrifugal VAD arises from its higher operating speed and lower gap size. Furthermore, at the required conditions for blood flow in the human body, the centrifugal VAD has higher efficiency than axial VAD.

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The pressure-time method is a flow rate measurement technique generally employed in hydropower plants to evaluate the efficiency of hydraulic turbines. The 1D numerical simulation incorporating the finite volume method is employed to evaluate the method. The results are compared with the experimental data. The flow is simulated inside a straight pipe with Reynolds number Re=6.76×〖10〗^6. The flow rate reduction curve is employed for the simulation of the deceleration part of the flow, before valve closure, in the pressure-time method. The effective parameters on the flow rate calculation including the friction losses and the definition of the final time of the valve closure are studied in detail. The increase in the accuracy of the flow rate calculation is a function of the increase in the accuracy of the friction loss calculations. The effect of several friction factors proposed for the evaluation of the unsteady flow is studied on the accuracy of the flow rate calculation. The Pezzinga friction factor shows the least error in the flow rate calculation. The available methods to find out the final time of integration still show a large error. A new method is proposed for the flow rate estimation without any need to have the exact time of the valve closure with an acceptable accuracy.

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Hydro screw is a small micro-hydro turbine. Due to increase in demand for clean energy production, a comprehensive project at the Iranian Research Organization for Science and Technology (IROST) for the design and construction of very small turbines (micro-turbines), including hydro screw, has been developed. Hydro screw is suitable for a low head and discharge that does not have a guide vane and draft tube; thus, it is simple, small, inexpensive, and portable. This turbine, with a 15 cm blade diameter, can generate power up to 2 kW. Hydro screw blade is inspired by the Archimedes turbine, and difference between them is that the blade pitch of hydro screw is variable and horizontally mounted. In this project, the effect of spiral variable pitch on turbine has been studied numerically. Based on the results, it was found that the turbine had the best efficiency at a spiral pitch of 1.5. Subsequently, the small model of hydro screw was made and tested in the laboratory. The results of this study have been presented in the form of standard curves of turbine performance and the accuracy of the results has been proved by comparison of numerical and experimental results. The results show the integrity of the numerical calculations and, therefore, they can be used in line with next turbine studies. The results indicate that the maximum turbine output is between 62% and 68%.
 

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Purpose: The purpose of the current research is to dry apples using a solar dryer with an absorbent cycle in two modes of direct-convective radiation and indirect-convective radiation. Two types of direct and indirect drying methods with and without moisture absorbers and drying in open air were used. The pre-prepared apple slices (flavored with cinnamon) were placed on a piece of mesh with certain dimensions, the initial weight of the samples was measured and inside the solar dryer with an absorbent cycle in two modes of direct-convective radiation and indirect-convective radiation. It was placed; And during the drying process, the rate of evaporation, texture, wrinkling, water reabsorption rate, retention rate of vitamin C (ascorbic acid) and color change and sensory characteristics at different levels of treatment (30% sucrose and without sucrose and zero, 0.5, 1 and 2% of cinnamon) and also some samples were dried by solar dryer without flavoring with cinnamon alone. Data analysis was done with the completely random factorial design statistical method and using SPSS version 26 statistical software.

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Strawberry is a perishable fruit and gray mold is one of the main reasons which reducing its shelf life. Due to the limitations of using chemical poisons, it seems necessary to use safe methods such as the use of essential oils (EOs) and edible coatings to control this fungus maintain the quality, and increase the storage period. However, the high volatility of EOs and organoleptic effects on agricultural products have hindered the direct application of EOs. This study is designed to enhance the shelf life of strawberries by designing nanoemulsion systems of EO with chitosan as follows: in the first experiment, the effect of nanoemulsion of the thymol, one of the main components of thyme, with a concentration of 5 g/L, alone and in combination with chitosan (CH) biopolymer was investigated on Botrytis cinerea. All treatments significantly reduced fungal growth compared to the control sample. Also, combined treatment showed the highest level of inhibition of B. cinerea. The second experiment was performed to evaluate the quality changes and post-harvest wastes of strawberries during storage. In this section, the fruits were coated with thymol 0.5%, thymol nanoemulsion 0.5%, and thymol nanoemulsion 0.5% + CH 0.5% and kept at 4 °C. Results presented that the application of the applied treatments had a positive effect on the physicochemical and biochemical indicators of strawberry fruit during the post-harvest period and caused better preservation of firmness, prevented weight loss and reduced microbial load. Also, the lowest rate of weight loss, the highest rate of firmness, and the lowest rate of growth of microorganisms were observed in covered fruits with treatment of thymol nanoemulsion 0.5% + CH 0.5%. Finally, this treatment can be suggested as a suitable cover to maintain the quality and reduce post-harvest waste of strawberries.