Comparison of Stellite coatings on low carbon steel produced by CGS and HVOF spraying

Stellite alloys are of great interest in industries due to a unique combination of high temperature mechanical strength, outstanding wear and corrosion resistance. Different thermal spraying processes are used for deposition of stellite alloys on industrial components. However, the investigations on the structure-property relationship of these alloys produced via different deposition process are limited. This study focuses on the microstructure, oxidation, and tribo-mechanical properties of Stellite 21 deposited by cold gas spraying (CGS) and high velocity oxy-fuel (HVOF) process on a low carbon steel substrate. The coating cross- section was characterized by SEM and optical microscopy. The coatings were further characterised by using nanoindentation, adhesion, and ball-on-disk wear tests. Moreover, XRD tests were run on the powder and the coatings to reveal possible phase transformation during spraying, as well as during wear and oxidation tests. The results showed no phase transformation in the as-sprayed CGS coating, besides higher values of porosity and oxide phase in the HVOF coating. However, an fcc-to-hcp phase transformation occurs at the surface layer of both types of coating during the ball-on-disk wear test. The presence of continuous oxide networks in HVOF coatings leads to delamination during the wear test. Overall, the CGS Stellite 21 coatings exhibit better performance than HVOF coatings in wear and oxidation tests

Robust identification of Parkinson\u27s disease subtypes using radiomics and hybrid machine learning

OBJECTIVES: It is important to subdivide Parkinson\u27s disease (PD) into subtypes, enabling potentially earlier disease recognition and tailored treatment strategies. We aimed to identify reproducible PD subtypes robust to variations in the number of patients and features. METHODS: We applied multiple feature-reduction and cluster-analysis methods to cross-sectional and timeless data, extracted from longitudinal datasets (years 0, 1, 2 & 4; Parkinson\u27s Progressive Marker Initiative; 885 PD/163 healthy-control visits; 35 datasets with combinations of non-imaging, conventional-imaging, and radiomics features from DAT-SPECT images). Hybrid machine-learning systems were constructed invoking 16 feature-reduction algorithms, 8 clustering algorithms, and 16 classifiers (C-index clustering evaluation used on each trajectory). We subsequently performed: i) identification of optimal subtypes, ii) multiple independent tests to assess reproducibility, iii) further confirmation by a statistical approach, iv) test of reproducibility to the size of the samples. RESULTS: When using no radiomics features, the clusters were not robust to variations in features, whereas, utilizing radiomics information enabled consistent generation of clusters through ensemble analysis of trajectories. We arrived at 3 distinct subtypes, confirmed using the training and testing process of k-means, as well as Hotelling\u27s T2 test. The 3 identified PD subtypes were 1) mild; 2) intermediate; and 3) severe, especially in terms of dopaminergic deficit (imaging), with some escalating motor and non-motor manifestations. CONCLUSION: Appropriate hybrid systems and independent statistical tests enable robust identification of 3 distinct PD subtypes. This was assisted by utilizing radiomics features from SPECT images (segmented using MRI). The PD subtypes provided were robust to the number of the subjects, and features

Epidemiology of Guillain-BarréSyndrome in Iranian Children Aged 0-15 Years (2008-2013)

Abstract Objective: Guillain-Barre Syndrome (GBS) is an acute inflammatory polyneuropathy characterized by a rapid progressive symmetric weakness. This is the most common cause of Acute Flaccid Paralysis (AFP) in most parts of the world. This study was carried out to investigate the epidemiological features of GBS in Iranian children. Materials & Methods: Data were extracted using the AFP surveillance system: a National screening program to detect all cases of AFP aged 0-15 years, around the country. National Population Statistics data and AFP demographic data during 2008-2013 intervals was obtained from the relevant authorities in ministry of health. GBS cases were then extracted from this data base. Chi-square and Fisher's exact test were used for statistical analysis. Results: 1884 cases of GBS were identified in years of study and average annual incidence rate was 1.72 per 100,000 populations. The highest incidence rate was in the range of 0-5 years. There was no statistically significant relation between the incidence of GBS and the season in the whole country. Conclusion: High costs of GBS treatment, morbidity and occasional mortality and the number of new cases which is estimated to be about 300 people per year, need particular attention of health system

Assessment of improved modal pushover analysis for eccentrically braced frames

This paper concentrates on evaluation of current Pushover Procedures to assess the seismic demands of Eccentrically Braced Frame (EBF). Three 5, 10 and 15 storey EBF frames, designed by Iranian codes, analyzed for five ground motions by MPA, IMPA, and as a proposed method MPA based on Energy-Based capacity curve (briefly E-B.MPA), also story drift of frames were estimated by conventional pushover using two Load distributions of FEMA-356, ELF and uniform patterns. It was considered, the 10 and 15 storey frames have reversal capacity curves, therefore the pushover curve of another story (not roof) was plotted to perform MPA but E-B.MPA was done with no difficulty. Comparing the responses of procedures with the results of Nonlinear Time History Analysis (NTHA) demonstrates that MPA.E-B determines drift demands of models with reversal capacity curves more accurate than other procedures. Moreover there are serious concerns about estimated drift demands of two load patterns

The Comparative Analysis of the Effect of Magic Spell on Prophet Muhammad (PBUH) in Sahih Bukhari and Sahih Muslim with Regard to the Circumstance of Revelation for Surah an-Nas and Surah al-Falaq

Some of the Ahadith in Sahih al-Bukhari and Sahih al-Muslim about casting a magic spell on Prophet Muhammad have made Sunni commentators and Muhaddithin relate the circumstance of revelation for Surah al-Falaq and Surah an-Nas to casting a magic spell on Prophet Muhammad by someone called Labid bin A’sam Yahudi. Sunni commentators thus recognize that this event is not against the infallibility of the Holy Prophet and his dignity of Nabuwwat. This article aims to answer this research question: Can the event of casting a magic spell on the Holy Prophet by Labid bin A’sam in Medina, as it is mentioned in some of the Ahadith, be the circumstance of revelation for Surah an-Nas and Surah al-Falaq? The results of the study show that due to some discrepancies between commentators on whether these chapters are Makki or Madani, some contradictory traditions on their circumstance of revelation, the referential and conceptual weakness of  the traditions about the magic spell on the Prophet, and stylistics of the above chapters having a Makki context, it is concluded that the circumstance of revelation for the above chapters cannot be attributed to the event of casting a magic spell on the Holy Prophet. © Seyed Mousavi, S.H; Mortazawi, S.M; Abdollah Zadeh, S.H. (2020) The Comparative Analysis of the Effect of Magic Spell on Prophet Muhammad (PBUH) in Sahih Bukhari and Sahih Muslim with Regard to the Circumstance of Revelation for Surah an-Nas and Surah al-Falaq. Biannual Journal of Comparative Exegetical Researches, 6 (11) 253-276.  Doi: 10.22091/ptt.2020.3366.138

Therapeutic Effects of Laser on Partial Osteotomy in the Rat Model of Hypothyroidism

Introduction: Several experimental studies have displayed positive result for laser radiation on stimulating bone regeneration in recent years. The purpose of this experimental study was to determine low-level laser (LLL) effects on partial bone defects in hypothyroidism male rat.Methods: Forty male Wistar rats were randomly distributed as below groups: hypothyroidism + laser (Hypo + laser), hypothyroidism (Hypo), and control. Four weeks after surgery, the tibia bone was removed. Biomechanical and histological examinations were performed immediately.Results: Our results showed significant reduction in the absorption of energy, resistance in bending deformation (bending stiffness), maximum force, high stress load, trabecular bone volume, and number of osteocytes, osteoblasts and osteoclasts in the osteotomy site in hypothyroidism rats compared to hypothyroidism + laser group (P < 0.05).Conclusion: The results indicated that using laser may improve fracture regeneration and it may accelerate bone healing in hypothyroidism rat

Biotechnique identification of breeding & cultivation of rabbitfish (Siganus sutor) until 2.5 cm stage in Hormozgan province

This project was conducted to determine The Bio technique of Reproduction and larvae Rearing of Rabbitfish (siganus sutor) till fingerling stage (2.5 centimeter TL) in Hormozgan province (North of Persian Gulf) during years 2010-2013 . preadults and adults were captured from coastal area of Bandar-e Lengeh and Lavan Island .The effects of synthetic hormones, LHRHa2 and HCG in variety days of reproduction season were surveyed. Fecundity, eggs diameter, fertility, Hatching, and survival rate were computed. Effects of salinity, light severity and tank size (30 L aquarium 300L poly ethylene tank and 2400 L fiber glass tank) on survival rate were surveyed, although Breeding of fish e\were successful in years 2011 and 2012 but larvae were only reared in year 2012. Results revealed that, if hormone injection efforts fulfill during April 1st to may 15th, Siganus sutor will surely spawn. Results revealed that average diameter of fertilized eggs was about 625.05 ±6.15 µ and there were 5570± 105 eggs in each gram According the results the rate of hatching and larvae survival was higher in 300L poly ethylene tank and 2400 L fiber glass tank than 30 L aquarium. The most mortality was observed during days 3-7 after hatch. There was not any difference between survival rate of larvae in various salinity. The best light situation for larvae was 2000 lux. under strong light , mortality of larvae increased. Growth of larvae was very slow in first 15 days after hatch but after that increased quickly .length of larvae in the first day was about 2.97±0.07 mm. on the day 45 , larvae gained the length of 3.56±0.4 cm. According to the results, although, breeding, seed production, larvae rearing and broodstock suppling of siganus sutor is possible but more Research to diversify the live food wich is used to feed larvae and also to increase survival rate of larvae must be perform

Pre- and post-treatment of α-Tocopherol on cognitive, synaptic plasticity, and mitochondrial disorders of the hippocampus in icv-streptozotocin-induced sporadic Alzheimer’s-like disease in male Wistar rat

ObjectiveMost dementia cases in the elderly are caused by Alzheimer’s disease (AD), a complex, progressive neurological disease. Intracerebroventricular (ICV) administration of streptozotocin (STZ) in rat’s results in aberrant brain insulin signaling, oxidative stress, and mitochondrial dysfunction that impair cognition change neural plasticity, and eventually lead to neuronal death. The current study aims to define the neuroprotective action of alpha-tocopherol in enhancing mitochondrial function and the function of synapses in memory-impaired rats brought on by icv-STZ.MethodsMale Wistar rats were pre-treated with (α-Tocopherol 150 mg/kg) orally once daily for 7 days before and 14 days after being bilaterally injected with icv-STZ (3 mg/kg), while sham group rats received the same volume of STZ solvent. After 2 weeks of icv-STZ infusion, rats were tested for cognitive performance using a behaviors test and then were prepared electrophysiology recordings or sacrificed for biochemical and histopathological assays.ResultsThe cognitive impairment was significantly minimized in the behavioral paradigms for those who had taken α-Tocopherol. In the hippocampus of icv-STZ rat brains, α-Tocopherol ocopherol effectively prevented the loss of glutathione levels and superoxide dismutase enzyme activity, lowered mitochondrial ROS and mitochondrial membrane potential, and also brought about a decrease in Aβ aggregation and neuronal death.ConclusionOur findings demonstrated that by lowering neurobehavioral impairments caused by icv-STZ, oxidative stress, and mitochondrial dysfunction, α-Tocopherol enhanced intracellular calcium homeostasis and corrected neurodegenerative defects in the brain. These findings examine the available approach for delaying AD connected to mitochondrial malfunction and plasticity issues

The Effects of Phase Transformation on the Structure and Mechanical Properties of TiSiCN Nanocomposite Coatings Deposited by PECVD Method

In the present study, the effects of phase transformations on the structure and mechanical properties of TiSiCN coatings were investigated. TiSiCN nanocomposite coatings were deposited on AISI H13 hot-work tool steel by a pulsed direct current plasma-enhanced chemical vapor deposition process at 350 or 500 °C, using TiCl4 and SiCl4 as the precursors of Ti and Si, respectively, in a CH4/N2/H2/Ar plasma as the source of carbon and nitrogen and reducing environment. Some samples deposited at 350 °C were subsequently annealed at 500 °C under Ar atmosphere. Super hard self-lubricant TiSiCN coatings, having nanocomposite structure consisting of TiCN nanocrystals and amorphous carbon particles embedded in an amorphous SiCNx matrix, formed through spinodal decomposition in the specimens deposited or annealed at 500 °C. In addition, it was revealed that either uncomplete or relatively coarse phase segregation of titanium compounds was achieved during deposition at 350 °C and 500 °C, respectively. On the contrary, by deposition at 350 °C followed by annealing at 500 °C, a finer structure was obtained with a sensible improvement of the mechanical properties of coatings. Accordingly, the main finding of this work is that significant enhancement in key properties of TiSiCN coatings, such as hardness, adhesion and friction coefficient, can be obtained by deposition at low temperature and subsequent annealing at higher temperature, thanks to the formation of a fine grained nanocomposite structure

Investigation of stock condition of Lengeh pearl oyster Pinctada radiata in western Hormozgan province habitats with emphasis on ecological agents

Pearling in Northern Persian Gulf has barred since 2006. Population dynamic and investigation of stock condition of pearl oysters has not done in thease area in thease years heretofore. For identification of habitats of Pinctada radiata, mohar oyster, primary sea tours in coastal waters of 11 regions in Lavan Island, 11 regions in hendorabi Island and 6 regions in Nakhiloo and Michaeil Ports, for early survey were done. 2 habitats in Lavan waters and 2 habitats in Hendorabi waters were identified and for investigation of stock condition, were sampled from autumn 2011 to summer 2012, seasonality. Belt transects andrandom quadrates method was used in this sampling. Physicochemical parameters in depth range of thease habitats was evaluated by CTD in first sea tour of stock sampling. Lavan 1 habitat, had maximum area, maximum total stock, maximum CPUA, maximum CPUE and maximum biomass, among other habitats, equal to 60ha, 357000N, 0.6N/m^2, 119N/hr and 4620kg respectively. Biometric data in Hendorabi2 habitat was rather than other habitats, significantly (P<0.01). Infinity length, L_∞, was calculated in Lavan1, Lavan2, Hendorabi1 and Hendorabi2 habitats, equal to 89.16, 87.68, 86.11 and 86.42 mm respectively. Growth constant, K, was estimated in Lavan1, Lavan2, Hendorabi1 and Hendorabi2 habitats, equal to 0.43, 0.44, 0.47 and 0.56 year^-1, respectively. Natural mortality constant, M, was calculated in Lavan1, Lavan2, Hendorabi1 and Hendorabi2 habitats, equal to 0.73, 0.75, 0.78 and 0.88 year^-1, respectively. Results of this project showed, area of investigated habitats, oysters stock of them and CPUA, have diminished in thease years, and interdict of pearl oysters catch was not able to revival of stocks. Majority of physicochemical parameters in depth ranges in surveyed habitas, had significant difference (P<0.01). Water turbidity in Hendorabi2 habitat was rather than other habitat, significantly (P<0.01), as subsidiary of high sedimentation in this habitat and main reason of high natural mortality constant, M, low settlement rate and absence of lower scale of oysters length in Hendorabi2 habitat