---

Abstract

Research Subject: Other waste incinerators and other high-temperature systems designed to dispose of garbage are referred to as heat treatment systems. The burning of waste materials, such as garbage, converts them into ashes collected on the waste floor, exhaust gases, very small particles and, most importantly, heat, which can be used to generate electrical power.

 

Research Approach:

In this research, firstly, the energy and exergy efficiencies of a waste incineration cycle, along with utilization of Lorestan petrochemical waste as an additional fuel for waste incineration, are investigated. In this way, the amount of energy needed to produce the required water vapor to disable the catalyst Ziegler-Nata was calculated for the production of linear stylistic polyethylene. Subsequently, a simple model for the inactivation reaction of Ziegler-Nata catalysts was presented using the steam generated by the waste incinerator, and then the mathematical equations for these reactions were obtained using the primary reaction law. By introducing these reactions into the reaction model, a new equation for the reaction model was obtained that covers the moments after the time of deviation to an acceptable level. This indicates the overcoming of inactivation reactions on the reactions of active centers production in the final stages of the reaction.

Main Results: The energy and exergy efficiencies of the waste incineration cycle along with the use of Lorestan petrochemical waste as an additional waste gas were investigated and thus the amount of energy needed to generate steam to disable Natal Ziegler catalysts in the production of linear linear polyethylene was calculated. To initiate this, the combined cycle was proposed and its energy and exergy efficiencies were investigated. Also, by changing the key components such as the ammonia solution composition, the ammonia distillation temperature and the input and output pressures of turbine, a way to achieve the energy needed to generate the steam needed to deactivate the Nitra zigzag catalyst in the production of linear linear polyethylene was developed.

 

---

Thai students’ writing in English is a chronic problem documented in the literature of English Language Teaching (ELT) in Thailand. However, little research has been conducted on how Thai teachers and students perceive the importance of English-writing and what difficulties and expectations/suggestions they have in teaching and learning this skill at upper-secondary schools (U-SS). This study, therefore, plans to fill this gap by employing two sets of surveys and semi-structured interviews with 114 teachers and 170 students from 30 different U-SS in the Northeastern part of Thailand and two provincial supervisors of Foreign-Language-Education Divisions (Pro-Sup). Besides their various stated personal and contextual problems in terms of time constraint, insufficient resources and poorly-motivated and mixed-ability students, national test structures and the presence of untrained English teachers, the participants acknowledged the importance of English-writing and expected to have this skill taught at all school levels. These findings suggest that to improve the teaching and learning practices of this skill at U-SS in Thailand and other countries with similar contexts, relevant support and necessary reforms from teachers, school leaders and national-test and policymakers are needed.

---

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).
 

---

The impact of different crop production systems was investigated on incidence of insect pests and their natural enemies, soil microflora and enzymatic activity, and quality of fruits produced in spring planted tomato at Ludhiana, Punjab, during 2017 to 2019. Production systems included conventional farming whereby indiscriminate and excessive use of agrochemicals is practiced, organic farming, and farming following Good Agricultural Practice (GAP) with IPM adoption. Higher Aphis gossypii and Helicoverpa armigera infestation was observed in organic fields followed by IPM and conventional fields. Aphid population showed a negative correlation with maximum and minimum temperature but a positive correlation with relative humidity, while the tomato fruit borer showed a positive correlation with maximum and minimum temperature but negative correlation with relative humidity and rainfall. The mean fruit yield in the farming system following IPM was maximum (50120 Kg ha^-1) followed by conventional farmers’ fields (408.1 q/ha) and organic fields (403.9 q/ha). The mean spider population under organic conditions (0.39-0.56) was significantly higher than that of IPM (0.26-0.36) and conventional farmers’ fields (0.02-0.10). Soil samples from conventional fields revealed the presence of quinalphos and chlorpyriphos, while tomato fruit samples showed the presence of triazophos and mancozeb during 2017 and 2018. In 2017, the flavonoids and percent antioxidant activity in fruits from organic field were higher. The bacterial count in organic and IPM field soil increased from 5.4×10⁷ and 4.9×10⁷ CFU g^-1 in 2017 to, respectively, 7.1×10⁷ and 6.5×10⁷ CFU g^-1 in 2019. The activity of alkaline phosphatase and urease was highest in organic fields.