bluuebunny/crossref_metadata_2025 huggingface dataset:
Spondias mombin Linn. (Anacardiacea) Essential Oil Ointment Enhances Healing of Excision Wounds in Rats
Authors: Agbaje Esther Oluwatoyin , Charles Omiyale Olumakinde
Published: August 2022

Background: Wound healing remains a challenging clinical problem, and correct, efficient wound management is essential. Various formulations of Spondias mombin Linn. (Anacardiaceous) is used in the folk medical therapeutics of Africa due to their anti-inflammatory effects and ethnomedicinal claims. Objective: To evaluate the re-epithelization, rapid wound healing and antioxidant activities of Spondias mombin Linn. (Anacardiaceous) leaves essential oil (SMEO) through excision in vivo model. Materials and Methods: Thirty-eight male rats weighing 250 ± 20g were used. Random grouping into n=6 rats; Group 1 received 50 µL of 1% SMEO, Group 2 received 0.1% of DMSO and Tween 20 (Control), Group 3 received Dermazin® ointment, Group 4 was untreated, Group 5 received 50µL of 10% SMEO, Group 6 received 50 µL of 15% SMEO, were treated for 14 days. In vivo wound healing rat model was employed with tissues of two rats harvested per group on the 3rd , 10th and 14th days after excision for histological analysis. The SMEO of (25–100 μg/ml) was passed through DPPH, Nitric oxide, Reducing power assays. Results: The antioxidant assays showed scavenging of species in close comparison with standard in a dose dependent manner. The essential oil showed promising results even at low concentration of 1%. The 10% and 15% wound contraction progression showed efficiency over the standard. Macroscopic observation and Histological analysis revealed a significant wound healing process of the treatment groups compared to the vehicle-treated and unwounded controls, after the 3rd, 7th and 14th day. Conclusion: The essential oil showed ability to initiate re-epithelization, proliferative stimulation of new blood vessels, collagen fibre synthesis and overall improved wound healing better than the standard (Dermazin®), therefore, a possible presentation as lead for drug development.
Farmer's Perception of Fruit Fly Bactrocera spp. in Mandarin Orange and their Management in Sankhuwasabha District of Nepal
Authors: Rai A , Sah L P , Adhikari K , Shrestha K
Published: August 2022

The study was conducted from October to December, 2020 to evaluate farmers' understanding of loss incurred by Bactrocera spp. on mandarin orange and practices adopted by farmers for their management. Eighty households of mandarin orange growers and 15 agro-vets were purposively selected and information was collected using a semi structured questionnaire. The findings indicated severe infestation of fruit fly in mandarin with 53% of the farmers having low (>15%), 36% having medium (15-30%) and 11% having high (>30%) level of fruit damage in their orchards. The survey identified several management practices like collection and destruction of fallen fruits, pruning, use of traps and chemical pesticides in controlling fruit fly. About two-third (61.25%) of the respondents used chemicals and 15% of the farmers collected and destroyed affected fallen fruits. Some farmers also practiced pruning in the study area for the control of fruit fly. The use of traps was a rarity and its use was limited to only 10% of the total respondents. Since farmers were not much aware of the impact, life cycle and different species of fruit fly, lacked adequate training, support, and supervision, effective management of fruit fly was not possible and resulted in a much greater damage in mandarin fruit.
Pathotypes Diversity of Puccinia striiformis causing Yellow Rust of Wheat in Nepal
Authors: Baidya S , Magar P B , Basnet R , Aryal L , Acharya B , Gupta G R , Pant K R , Subedi M , Karki A , Joshi P , Bhandari D
Published: August 2022

Wheat (Triticum aestivum) is one of the major stable crop in Nepal. The area of cultivation of wheat is increasing compared to last decade; but its productivity is almost stagnant due to several limiting factors among them, yellow rust caused by Puccinia striiformis is one of the major responsible factors. Rust monitoring was carried out to determine the pathotypes diversity of P. striiformis during 2018-2021. A total of 109 samples were collected from 41 districts of seven provinces. Each yellow rust samples multiplied in susceptible cultivar and inoculated in differential set for rust pathotypes analysis. The diversity of pathotypes was observed across the country. Seven pathotypes (238S119, 110S119, 46S119, 47S103, 6S0, 78S84 and 110S84) were recorded with different severity level. The pathotypes 46S119, 110S119 and 238S84 found as predominant in different locations. The severity level ranged from resistant to highly susceptible depending on location and genotypes. The severity level was comparatively higher in western-mid-hill than eastern-mid-hill. The change in pathotypes diversity may be resulted by selection pressure due to the adoption of new wheat genotypes. Monitoring rust pathotypes is essential to develop a strategic plan for yellow rust management by deploying resistant gene/s in wheat genotypes.
Asian Citrus Psyllid Diaphorina citri (Kuwayama) (Hemiptera: Liviidae) and its Detection Survey in Citrus Orchards of Sindhuli, Nepal
Authors: Dhakal N , Adhikari D , Subedi K , Subedi A , Tiwari D B , Bajracharya A S R , Humagain S P
Published: August 2022

Citrus greening, also known as Huanglongbing (HLB), is one of the world's most devastating citrus diseases. In Asia, including Nepal, the disease is vectored by Asian citrus psyllid (Diaphorina citri (Kuwayama)) that transmits the pathogen Candidatus Liberibacter asiaticus, which is a fastidious, phloem-limited bacterium. Recently, the Sindhuli district of Nepal, well-known for sweet orange production, has been suspected of this destructive disease. Therefore, a detection survey on the vector was conducted by Plant Quarantine and Pesticide Management Centre, Lalitpur, in coordination with Prime Minister Agriculture Modernization Project, Project Implementation Unit, Sindhuli, during the second week of April 2021. The survey carried out on six major citrus growing pockets in the Sindhuli district revealed the presence of D. citri in the citrus orchards of Golanjor rural municipality ward no. 3, Sindhuli. Also, it was found that 2.96 percent and 20 percent of the surveyed citrus orchards of Sindhuli and Golanjor-3 were infested by D. citri, respectively. The existence of the vector in the orchards has increased the chances of citrus greening occurrence; however, tests like Polymerase Chain Reaction (PCR) can be helpful for the further confirmation of the disease in the region. In addition, the government should organize campaigns to make the citrus growers familiar with its vector insect-citrus psyllid, HLB, and its preventive and curative management measures as soon as possible to minimize the losses from the disease.
माधवी उपन्यासकी माधवीको चारित्रिक विशेषता {A Characteristic Feature of Madhavi in the Novel Madhavi}
Authors: गैरे Gaire ईश्वरीप्रसाद Ishwariprasad
Published: August 2022

‘माधवी’ (२०३९) उत्तरवैदिककालीन समाजको ऐतिहासिक पुनर्निर्माण गरी प्रस्तुत गरिएको उपन्यास हो । यस उपन्यासमा पात्रलाई ऐतिहासिक विकासक्रमको संवाहकका रूपमा चित्रित गरिएको छ र उत्तरवैदिक कालको युगीनसन्दर्भलाई सिङ्गो सग्लो रूपमा देखाउनका लागि यस उपन्यासमा माधवीलाई नायिकाको भूमिकामा प्रस्तुत गरिएको छ । उत्तरवैदिक युगका तेह्रवटा जनपदको विकासको स्वरूप प्रत्यक्ष वा अप्रत्यक्ष रूपमा माधवीकै सन्दर्भबाट प्रकटिएका छन् । अहिच्छत्रको एक राजकुमारी, एक महामाया गणिका, गालवको गुरुदक्षिणा पूर्तिका लागि केशशुल्का बन्न बाध्यभएकी र चार ओटा सम्राटकी पुत्रप्रसू माता र अन्ततः गालवकी जीवनसँगिनी बन्न पुगेकी माधवीका विभिन्न चारित्रिक विशेषताहरू देखापर्दछन् । ती विशेषताहरूलाई विभिन्न आधारमा यस लेखमा विवेचना गरिएको छ । चारित्रिक विशेषताको विश्लेषण उपन्यासको विधासिद्धान्त अन्तर्गत पात्रविश्लेषणको सिद्धान्तका आधारमा गरिएको छ । अध्ययन गुणात्मक पद्धतिमा गरिएको छ र वर्णनात्मक एवं विवेचनात्मक विधिमा विश्लेषण गरिएको छ । सिङ्गो उत्तरवैदिकयुगको प्रस्तुतिको माध्यम बनेकी माधवी यस उपन्यासकी माधवी महत्वपूर्ण पात्र हो भन्ने यस लेखको निष्कर्ष हो ।
{Madhavi (2039 B. S.) is a novel that presents a historical reconstruction of post-Vedic society. The protagonist in this novel is portrayed as an agency of historical developments. In this novel, Madhavi is presented in the role of a heroine to show the epochal context of the post-Vedic period in its entirety. The pattern of development of the thirteen countries of the post-Vedic period is directly or indirectly revealed in the context of Madhavi. Madhavi, a princess of Ahichchhatra, a Mahamaya courtesan, was forced to become a keshashulka (courtesan) to fulfill Galav's Gurudakshina and became the mother giving birth to four emperor sons and eventually became Galav's life partner. These features are discussed in this article on various grounds. The Characteristic analysis is done based on the character analysis principle under the theory of the novel genre. The study is conducted in a qualitative methodology and is analyzed in a descriptive and critical method. This article concludes that Madhavi is a significant character in this novel, which has become the medium of presentation of the entire post-Vedic era.}
अष्टाध्यायी व्याकरणमा सूत्रशैली {The Formulation Style of the Sutra in Ashtadhyayi Grammar}
Authors: ढकाल Dhakal दीपकप्रसाद Dipakprasad
Published: August 2022

प्रस्तुत लेख अष्टाध्यायी व्याकरणमा सूत्र शैलीको अध्ययनमा केन्द्रित छ । अष्टाध्यायी पाणिनि (इ. पू. ४५०—४००) द्वारा वैदिक र लौकिक संस्कृतमा भएका भाषिक व्यवस्थालाई नियमन गरिएको व्याकरण हो । करिब चार हजार सूत्रलाई पाणिनिले तिनको प्रकार्यका आधारमा प्रस्तुत गरेका छन् । यी सूत्रले व्याकरणमा विशेष शैलीगत स्वरूप प्राप्त गरेका छन् । यस व्याकरणको अन्य पक्षबाट अध्ययन भए पनि सूत्रको प्रकार तथा तिनका बिचको पारस्परिक अन्तरनिर्भरताका विषयमा अध्ययन भएको छैन । त्यही रिक्तताको परिपूर्तिका लागि अध्ययन गर्नु यस लेखको मुख्य उद्देश्य हो । त्यसका लागि सामग्री सङ्कलन पुस्तकालयीय कार्यद्वारा गरिएको छ । सङ्कलित सामग्रीको विश्लेषण वर्णनात्मक तथा व्याख्यात्मक विधि प्रयोग गरिएको छ । सूत्र, तिनका पदार्थगत अन्वय र सङ्क्षिप्त नियमनका स्वरूप दिएर शोध्य विषयलाई सामान्यीकरण गरिएकाले विश्लेषण निगमनात्मक पद्धतिमा आधारित छ । अष्टाध्यायीमा प्रस्तुत गरिएका संज्ञा, परिभाषा, विधि, नियम, अतिदेश, अधिकार गरी छ ओटा सूत्रका प्रकार एवं अध्याहार र अनुवृत्ति सूत्रकाबिचका प्रविधिगत अन्तर्सम्बद्धता हो भन्ने यस लेखको निष्कर्ष हो ।
{The present article focuses on the study of the formulation style of the sutra in Ashtadhyayi grammar. Ashtadhyayi is the grammar regulated on the linguistic system in Vedic and classical Sanskrit by Panini (450-400 BC). Panini has presented about four thousand sutrasbased on their functions. These sutras have acquired a special stylistic form in grammar. Although other aspects of this grammar have been studied, the type of sutra and the interdependence between them have not been studied. The main purpose of this article is to study to fill that critical gap. For that, data has been collected through library work. The descriptive and explanatory method of analysis of the collected data has been used. The analysis is based on the deductive method, as the subject matter is generalized by giving the form of the sutras, its semantic coherence, and brief regulation. This article concludes in Ashtadhyayi that there is a technical interrelationship between the types of six sutras, sanjna, paribhasha, vidhi, niyama, atidesha, adhikara and adhyahara and anuvritti.}
लोकवार्ताको अध्ययनक्षेत्र {The Area of Folklore Studies}
Authors: घर्ती Ghartee दुर्गाबहादुर Durgabahadur
Published: August 2022

बलम लोकवार्ता अहिले अध्ययनको एउटा महत्वपूर्ण विषयका रूपमा स्थापित भएको छ । यसको क्षेत्रअन्तर्गत लोकमा परम्परागत एवं मौखिक रूपमा प्रचलित कला, सिप र ज्ञानका यावत् कुराहरू पर्दछन् । लोकवार्ताको क्षेत्रलाई कतिपयले लोकसाहित्यमा मात्र सीमित गर्न खोजे पनि अहिले यो लोकसाहित्यका साथै लोकमानस, लोकसंस्कृति, लोककला, परम्परागत ज्ञान र सिपका सबै कुरा समेटिने विषय बनेको छ । त्यसैले यसका विषय विविध प्रकारका देखिन्छन् । लोकवार्ताका विषय, माध्यम र विधि भिन्न हुने भए पनि तिनका साझा विशेषताका आधारमा लोकवार्ताको वर्गीकरण गर्न सकिन्छ । यस विषयमा सङ्क्षेपमा वर्णन गरिएको पाइने भए पनि विस्तृत र गहन अध्ययन हुन सकेको पाइँदैन । त्यही रिक्तताको परिपूर्तिका लागि अध्ययन गर्नु यस लेखको मुख्य उद्देश्य हो । त्यसका लागि लोकवार्ता सिद्धान्तलाई आधार बनाइएको छ । पुस्तकालयीय कार्यद्वारा सामग्री सङ्कलन गरिएको छ र तिनको विश्लेषण व्याख्यात्मक एवं विवेचनात्मक विधिमा गरिएको छ । समाजका प्रचलित मूर्त र अमूर्त संस्कृति अन्तर्गत पर्ने सबै कुरा लोकवार्ताको अध्ययन क्षेत्रभित्र पर्दछन् । अमूर्त लोकवार्ता अन्तर्गत मौखिक लोकवार्ता, प्रदर्शनकारी लोककला, प्रथागत लोकवार्ता र भौतिक लोकवार्ता पर्दछन् र मूर्त लोकवार्तामा हस्तकला, वास्तुकला र भौतिक सामग्रीको निर्माण पर्दछन् भन्ने अध्ययनको निष्कर्ष रहेको छ ।

{Folklore has now been established itself as an important subject of study. Its scope includes all traditional and oral art, skills, and knowledge. Although some have tried to limit the field of folklore to folk literature, it has now become a subject of folklore as well as folk literature, folk psychology, folk culture, folk art, traditional knowledge, and skills. So there is a variety of its subject matter. Although this subject is briefly described, no detailed and in-depth study has been done. The main purpose of this article is to study to fill that gap although the subject, medium, and method of folklore differ, folklore can be classified on the basis of its common characteristics. The main objective of the present study isto identifies and classifies the field of folklore studies. For that, folklore theory is based. Data have been collected through library work and analyzed in an explanatory and critical method. Everything that falls under the prevailing tangible and intangible culture of the society falls within the field of folklore studies. The study concludes that intangible folklore includes oral folklore, performing folk art, customary folklore, and material folklore, and tangible folklore includes handicrafts, and folk crafts.}
सङ्कथन विश्लेषणमा डेल हाइम्सको सिद्धान्त {Dell Hymes's Theory in Discourse Analysis}
Authors: भट्टराई Bhattarai भरतकुमार Bharatkumar
Published: August 2022

प्रस्तुत लेख सङ्कथन विश् लेषणको थालनी र त्यसको विकासमा डेल हाइम्सको नवीन सिद्धान्त सम्प्रेषणको जाति सिद्धान्तले थपेको योगदानको मूल्याङ्कनमा केन्द्रित छ । फर्थको भाषिक दृष्टि, ह् यारिसको सङ्कथन विश्लेषण माथिको सर्वप्रथम विमर्श र मिचेलको विनिमय संरचनाको सूक्ष्म ढाँचालाई अँगालेर अगि बढेको सङ्कथन विश्लेषणको परम्परालाई नयाँ आयाम दिई डेल हाइम्सले मानवजातिले व्यवहार गर्ने भाषालाई सपिरले भनेझैँ मानवशास्त्रको अङ्ग तथा सस्युरले मानेझैँ सङ्केतविज्ञानको अङ्ग मान्दै सम्प्रेषणको जातित्व कसरी निर्धारित गरे अनि त्यसका आधारमा परम्परित व्याकरणको सीमाभन्दा माथि राखेर सांस्कृतिक सन्दर्भबाट हेर्दै सङ्कथनको स्तरमा व्याख्या गर्ने सैद्धान्तिक मान्यता विकसित गरे भन्ने समस्या यस लेखको रहेको छ तथा सो समस्याको समाधानार्थ सामग्रीको संयोजन र विश्लेषण गर्ने उद्देश्य यस लेखमा राखिएको छ । यसका लागि सङ्कथन विश्लेषणको सैद्धान्तिक आधार तथा डेल हाइम्सद्वारा प्रस्तुत सन् १९६२, १९६४ र १९७४ का कार्यहरूलाई विश्लेषणका प्रमुख सामग्री तथा तिनलाई सम्पुष्ट गर्ने विद्वान्हरूका अध्ययनलाई द्वितीयक सामग्रीका रूपमा प्रयोग गरिएको छ । लेखले निष्कर्षका रूपमा हाइम्स मानवभाषालाई बृहत्सम्प्रेषणात्मक घटकका रूपमा हेर्दै मानवको व्यवहारलाई जातिविशेषको पहिचान वा बोधका रूपमा विश्लेषण गर्ने अन्तर्दृष्ट भएका सङ्कथन विश्लेषक थिए र यो नवीन दृष्टि नै सङ्कथन विश्लेषणको परम्परामा उनको महत्वपूर्ण योगदान थियो भन् ने ठहर गरेको छ ।
{This article focuses on the beginning of discourse analysis and the evaluation of the contribution of Dell Hymes' new theory of ethnography of communication to its development. Dell Hymes gives a new dimension to developing the tradition of discourse analysis by em bracing Firth's linguistic vision, the first discussion on Harris's discourse analysis, and the subtle structure of Mitchell's exchange structure. The problem of this article is how Hymes believes that language is a part of semiotics as Saussure thinks it, and as Sapir says it, is an integral part of anthropology, how the ethnicity of communication was determined and on the basis of that, how he developed the theoretical notion of interpreting at the level of discourse from the cultural context beyond the limits of traditional grammar and the purpose of this article is to combine and analyze the data to solve this problem. For this, the theoretical basis of discourse analysis and the works of 1962, 1964, and 1974 presented by Dell Hymes have been used as the main data of analysis and the study of the scholars who completed it as secondary data. The article concludes that Hymes was a synthesis analyst with an insight into human language as a broad communicative component and an analysis of human behavior as an identity or perception of a particular race.}
‘म जुजुमान’ कथाको लकानेली मनोविश्लेषण {Lacanian Psychoanalysis of the Story 'Ma Jujuman'}
Authors: ढकाल Dhakal रजनी Rajani
Published: August 2022

प्रस्तुत लेखमा ‘म जुजुमान’ कथामा लकानेली परिकल्पना पद्धतिको प्रयोग कसरी भएको छ र त्यसले ‘गोठाले’का कथामा कस्तो प्रभाव पारेको छ भन्ने मूल जिज्ञासाको समाधान खोजिएको छ । गोविन्दबहादुर मल्ल ‘गोठाले’ मनोविश्लेषणात्मक कथा लेख्ने स्रष्टा हुन् र उनका कथालाई मनोविश्लेषणका फ्रायडेली र उत्तर फ्रायडेली सन्दर्भबाट अध्ययन गर्नु उपयुक्त हुन्छ । यस अध्ययनमा उत्तर संरचनावादी मनोविश्लेषक ज्याक लकाँको परिकल्पना–पद्धतिका कोणबाट अध्ययन गरिएको छ । मानिसको मनोजगत् आफ्नै मनको चेतन र अचेतनको द्वन्द्वमा रुमलिनुको मूल कारण समाज र भाषा हो र यसै द्वन्द्वमा मान्छेले अभाव, अस्पष्टता र अपूर्णताको अनुभव गरिरहन्छ भन्ने लकानेली मान्यतालाई आधार बनाई यस अध्ययनमा ‘गोठाले’ को म जुजुमान कथाको विश्लेषण गरिएको छ । सम्बद्ध कथाको सूक्ष्म पठन गर्दै मूल पात्र जुजुमानको द्वन्द्वरत मनोदशाको विश्लेषणबाट जुजमान पात्रमा देखिएको द्वैध चरित्र समाजको अवस्थाका कारण निर्मित भएको हो र परिकल्पना पद्धतिको प्रयोगले जुजुमानको चरित्रगत विशिष्टता मार्फत ‘गोठाले’ को यो कथा जीवन्त बन्न पुगेका छ । यस कथाले जुजुमानको मनोदशामार्फत तत्कालीन समाजको सङ्क्रमणकालीन समयलाई चिनाउन सफल भएको छ भन्ने निष्कर्ष यस अध्ययनमा निकालिएको छ ।
{This article explores the solution to the basic question of how the Lacanian imaginary is usedin the story 'Ma Jujuman' and how it has affected the story of the 'Gothale'. Govinda Bahadur Malla 'Gothale' is the author of psychoanalytic fiction and it is appropriate to study his storyin the context of Freudian and post-Freudian psychoanalysis. This study is analyzed from the perspective of post-structuralism psychoanalyst Jacques Lacan's imaginary. The study analyzes the story of the 'Gothale' from the lens of Lacanian psychoanalysis. This study is based on the Lacanian idea of that human mind is guided by the society and language. Due to this, thereis always conflict between the conscious and the unconscious mind. A meticulous reading of the related story reveals that the dual character seen in the main character, Jujuman's character is formed due to the state of society and the use of imagination that has made Jujuman's characteristic quite unique. The study concludes that this story has succeeded indentifying the transitional period of society through Jujuman's mood.}
पश्चिमी अद्यतन चिन्तन: उत्तरसिद्धान्त {Western Modern Thought: Uttarasdhanta}
Authors: शर्मा Sharma अमृतादेवी Amritadevi
Published: August 2022

Not available.
Предметный мир примет и поверий (Проживание смерти) / Priedmietnyj mir primiet i powierij (Prożywanije smierti)
Authors: Czerwiński Piotr
Published: August 2022

The paper deals with Russian folk tales and legends describing death, dying, actions and roles of their protagonists with regard not only to their present state and condition but also to their future ones. The image of Death as a significant figure has been characterized from the point of view of its various meanings. The world of objects is described as a special one with regard to the reality, influencing people and being influenced by them. The author suggests a number of attitudes towards the potential, virtual typologies connected with the meanings of the paradigmatic units. The units are also discussed in terms of their internal structure and position in general semantics.
Do Mexican TN-Visa swine caretakers’ euthanasia attitudes differ if they are male or female?
Authors: Yarian Jacob K , Skaar Brad , Johnson Anna K. , Stalder Kenneth J , Ross Jason W. , Millman Suzanne T. , Pairis-Garcia Monique D , Robles Ivelisse , Jass Cassandra
Published: August 2022

Currently, Hispanic and Latino caretakers makeup 17.2% of the total animal production and aquaculture workforce in the United States (U.S.). Yet, little is known about swine euthanasia attitudes between male and female caretakers. The objective of this project was to investigate if there were euthanasia attitudinal differences between male and female swine caretakers on a TN-visa from Mexico working on a commercial sow farm. An online Qualtrics survey was delivered in Spanish language and completed by 32 participants (16 males and 16 females). Eligible respondents were swine caretakers on a Trade NAFTA (TN) visa who spoke and read Spanish as their first language. Results will be presented descriptively. Caretaker mean average age was 32 yr (range 24 to 53 yr), and 97% had received a higher education, with 62% never euthanizing an animal prior to working with pigs. Average time living in the U.S. was 2.8 yr. Regardless of caretaker sex, all caretakers reported being confident, knowledgeable, could make decisions, and were comfortable in performing euthanasia. Furthermore, there were no differences when euthanasia was being considered for an adult pig versus a neonatal piglet. In conclusion, these results suggest pigs and piglets are likely to receive timely and humane euthanasia to alleviate suffering on-farm by male and female swine caretakers on a TN-visa from Mexico.
Advanced Microscopic Study of Suspension Plasma Sprayed Zirconia Coatings with Different Microstructures
Authors: Sokołowski Paweł , Pawłowski Lech , Dietrich Dagmar , Lampke Thomas , Jech David
Published: August 2022

The main purposes of applying the coatings on the surface of different components include the improvement of their functional and decorative properties. The functional properties of coating are strongly dependent on its microstructure. The main goal of the paper is to show the differences of two microstructures that can be obtained using suspension plasma spraying technology: (i) columnar one; and, (ii) lamellar, two-zone microstructure. Initially, the optimization of spray parameters was made and then the microstructural studies were performed. The work was focused on zirconia stabilized by yttria (YSZ) and both by yttria and ceria (YCSZ) which are most frequently used as thermal barrier coatings (TBC). Moreover, two types of microstructure were achieved using two different plasma torches, namely SG-100 of Praxair and Triplex of Sulzer Metco. After optimizing the spray parameters the microstructure of prepared coatings was analyzed using electron microscopy (SEM). The conventional SEM microscopy with secondary electrons detector (SE) and back scattered electrons one (BSE) were used. The energy dispersive spectroscopy (EDS) was performed to analyze the chemical composition. Finally, by electron backscatter diffraction (EBSD) grain shape, size and texture were determined for discussion of the coatings growth mechanism.
Cold Spray and Reaction Sintering of Ti-TiAl3 Composite Coatings
Authors: Leshchynsky Volf , Bielousova Oleksandra , Papyrin Anatoli
Published: August 2022

Recently a Ti–TiAl3 metal–intermetallic laminate (MIL) composite attracts growing attention because they have potential application in honeycomb or sandwich components of airplanes and as biomaterial with good bio-compatibility. Of the available processing techniques, diffusion bonding of elemental titanium and aluminum foils is an effective low-temperature method to synthesize the composite, allowing growth of the intermetallic layer. However, application of assembling and multi-pass cold rolling operations leads to fact that this technology is complex and expensive. The use of Cold Spray technology instead of aluminum foils utilization and multi-pass cold rolling to produce the Ti–TiAl3 MIL composites is believed to be more effective. However, reaction diffusion kinetics of Ti-Al particulate composite differs from that of classical MIL composite and needs to be studied. The task of this paper is to define microstructural changes of Tl-TiAl3 composite coating during cold spraying and reaction sintering. The optical microscopy, SEM, EDS, X-ray and microhardness examinations are presented and discussed.
Eliminating Hexavalent Cr Emissions in Thermal Spray Alloys
Authors: Cheney Justin , Gansert Daren
Published: August 2022

Chromium containing metals are an industry staple due to unparalleled corrosion resistance and durability. Unfortunately, many if not all Cr-containing alloys can produce Hexavalent Chromium (Cr6+), a known carcinogen. Studies conducted by the California Air Resources Board (CARB) showed that 30-60 percent of chromium emissions produced in thermal spray processing can contain Cr6+. In addition, several independent studies found that Cr6+ emissions produced from Twin Wire Arc Spray (TWAS) can be up to 3,000 times greater than the legal limits established by the CARB. This study details efforts to develop the next generation of high performance thermal spray alloys which are Chromium free, thereby resulting in zero Cr6+ emissions. In order to meet these objectives high throughput computational metallurgy was employed. The initial results have shown that next generation alloys can be developed to meet or exceed the performance of incumbent Cr-bearing alloys currently in service, and that the future of Cr-free alloys is on the horizon.
Formation of a Continuous β-NiAl Layer Near the Interface in a γ+β MCrAlY
Authors: Yuan Kang , Peng Ru Lin , Li Xin-Hai
Published: August 2022

A thermal cycling test was carried out in an EB-PVD MCrAlY – superalloy system, the result of which showed that a continuous β-NiAl layer formed in the MCrAlY coating near the coating–superalloy interface. Since β phase can be as a reservoir of Al, the formation of the β layer, in which much Al is reserved, is probably beneficial to the coating’s life. An oxidation-diffusion model was adapted to simulate the development of the microstructures in the coating-superalloy system. The simulation results indicate that the formation of the β layer was strongly related to the high Al activity in the substrate; if the Al activity of the substrate was high enough, a β layer could be built up in the coating near the coating-substrate interface.
High Temperature Oxidation of Cold Gas Sprayed Bond Coats for TBC Application
Authors: Lima C.R.C. , Belém M.J.X. , Crespo V. , Cano I.G. , Dosta S. , Guilemany J.M.
Published: August 2022

Plasma sprayed thermal barrier coatings (TBCs) have been extensively employed in most aerospace and land based turbine engines, permitting gas temperatures to be raised substantially above those for uncoated systems. Traditional TBC systems are composed of a metallic bond coat and a ceramic top coat both applied by plasma spraying. New deposition techniques have been proposed mainly for the metallic bond coat, like high-velocity oxy-fuel (HVOF) and more recently cold gas spray (CGS). CGS is an attractive technology that generates very dense coatings, without oxidation and maintaining the initial powder microstructure, characteristics that are potentially interesting for bond coat application. In the current study, TBCs with two sets of cold gas sprayed bond coatings were prepared and evaluated in high temperature isothermal oxidation tests. Measurements of sample mass as well as microstructure observations were carried out on the as sprayed and oxidized samples to compare the behavior of different bond coat chemical compositions. As sprayed oxidation degree, structural changes and bonding strength of the samples were also determined.
HVOF and HVAF Coatings of Nano-Agglomerated Tungsten Carbide–Cobalt Powders for Water Droplet Erosion Application
Authors: Tarasi F. , Mahdipoor M.S. , Dolatabadi A. , Medraj M. , Moreau C.
Published: August 2022

Water droplet erosion (WDE) is a well-known phenomenon. This type of erosion is due to the impingement of water droplets of several hundred microns to a few millimeters size at velocities of hundreds of meters per second on the edges and surfaces of components. The solution to this problem is in high demand especially for the moving blades of gas turbines’ compressors and those operating at the low-pressure (LP) end of steam turbines. Thermal sprayed tungsten carbide based coatings have been the focus of many studies and are industrially accepted for a multitude of wear and erosion resistance applications. The present work studies the microstructural, phase analysis and mechanical properties and their effects on water droplet erosion resistance of such coatings deposited with high velocity oxygen fuel (HVOF) and high velocity air fuel (HVAF) processes. The feed nano-agglomerated tungsten carbide-cobalt powders are in either sintered or non-sintered conditions. The WDE tests were performed using 0.4 mm water droplets at 300 m/s impact velocity. The study shows promising results for this cermet (better than the Ti6Al4V bulk material) as WDE resistant coatings when deposited using HVOF or HVAF processes under optimum conditions.
Laser Surface Patterning Pretreatment before Thermal Spraying—A Way to Adapt and Control the Surface Topography to the Considered Materials and the Stresses Imposed
Authors: Kromer Robin , Costil Sophie , Cormier Jonathan , Berthe Laurent , Peyre Patrice , Courapied Damien
Published: August 2022

Coating characteristics are very dependent on the substrate preparation and spray parameters. That’s why the surface must be adapted mechanically and physico-chemically to favor coating/substrate adhesion. Conventional surface preparation method as Grit-Blasting is limited by surface embrittlement and produces large plastic deformations throughout the surface resulting compressive stresses. Among all, Laser Surface Patterning is suitable to prepare the surface of sensitive material. It leads to several benefits such as surface free of Grit-Particle inclusions and improves directly the quality of coating bond strength so life-span. Finally, Laser Surface Patterning adapts impacted surface creating a large anchoring area. The essential idea here is to compare adhesion for two surface preparation methods Grit-Blasting and Laser Surface Patterning for two couples of materials used in aeronautic: Ni- Al and YSZ powder sprayed on 2017 aluminum alloy and AISI 304L stainless steel respectively. Optimized surface topographies can then be designed according to the materials as well as their applications.
Mechanism of Calcareous Deposit Formation on TSA-Coated Steel Structures at Elevated Temperatures
Authors: Paul S. , Harvey M.D.F. , Zulkfli N.S. , Yunus K. , Fisher A.C.
Published: August 2022

Thermally sprayed aluminum (TSA) has been used to protect offshore structures for many years at ambient temperatures. However, the melting point of aluminum, and the limited corrosion rate data indicate that they are likely to perform well in high temperature seawater as they tend to form calcareous deposits. Nonetheless, not much is known regarding the protection mechanism offered by TSA at elevated temperatures. This paper reports micro-scale surface characterization data on damaged TSA-coated carbon steel exposed to boiling synthetic seawater. The corrosion rate, calculated using linear polarization resistance (LPR) technique of TSA was ~10µm/year. This is very similar to the TSA corrosion rate observed at room temperature. The formation of a calcareous deposit which covers the exposed steel seems to reduce the corrosion rate. Detailed microstructural characterization of the calcareous was also carried out and the kinetic information regarding the rate of formation of calcareous deposits is also presented.
Microstructure and Tribological Properties of Liquid-Fuel HVOF Sprayed Fine WC-Co-Cr Coating
Authors: Upadhyaya Rohit , Shrivastava Sharad , Modi S.C. , Modi A.
Published: August 2022

This study compares high-velocity oxygen fuel spray MJP5000 and MJP 6000 (Patented by Metallizing Equipment Company Pvt Ltd.) using powder WC-Co-Cr. The microstructure and phase composition of powders and coatings will be analyzed by scanning electron microscopy and X-ray diffraction. Coatings were also characterized by their hardness, bond strength, roughness, deposition efficiency. Therefore, coating of high hardness and wear resistance can be produced with all HVOF spray system when the proper spray powder and process parameters are chosen. The results demonstrate that the powder exhibits various phase transformation during the spray process depending on type of powder, spray system and spray parameters.
A Numerical Investigation—Air Plasma Spraying by Means of a Three-Cathode Spraying Torch
Authors: Bobzin K. , Öte M.
Published: August 2022

Newly-developed multi electrode spraying systems have improved the process stability and coating properties in air plasma spraying (APS) significantly. The new generation three-cathode torches, i.e. TriplexProTM-200/210, can be operated without significant plasma fluctuations. In previous studies a numerical model, which couples fluid dynamic, electro-magnetic and thermal relationships to investigate the flow characteristics in the torch were introduced. In this study further development of the model with respect to meshing and turbulence model will be introduced. Furthermore, free jet simulations will be conducted which use temperature and pressure profile at the outlet of the torch as inletting boundary conditions. Advanced diagnostic methods will be implemented to verify the capability of the numerical models.
Al/Al2O3Cermets by Plasma Spraying—Optical Response of Experimental and Numerical Materials
Authors: Toru D. , Quet A. , Piombini H. , Bianchi L. , Echegut R. , De Sousa Meneses D. , Del Campo L. , Echegut P.
Published: August 2022

Normal hemispherical spectral reflectances of plasma sprayed Al2O3/Al cermets were measured from visible to infrared wavelengths for several metal concentrations ranging from pure alumina to aluminum. Microstructure and composition of the samples were carefully characterized to explain their optical response, highly dependent on volume and/or surface scattering. Besides their contribution to the knowledge of microstructure, 2D scanning electron microscopy and 3D micro-tomography images were exploited to get statistical data in order to generate simplified numerical samples. A Monte Carlo ray-tracing model was then intended to reproduce experimental trends of the optical spectra. A good agreement with the experimental data was obtained.
An Investigation on Microstructural Properties of Plasma Sprayed Tungsten Carbide Enhanced with Partially Stabilized Zirconia
Authors: Abuali Galedari S. , Salimi Jazi M. , Azarmi F. , Tangpong A. , Huang Y.
Published: August 2022

Tungsten carbide coatings are often applied to improve surface properties such as wear, high temperature degradation, and corrosion resistance. Zirconia coatings have also been used extensively in various industries due to their excellent tribological and insulation properties combined with high stiffness. It is speculated that adding zirconia to tungsten carbide may result in a coating with combination of excellent thermal and mechanical properties of constituents. In the current study, a powder mixture of 50 wt. % WC-Ni and 50 wt. % ZrO2-Y2O3 deposited on a low carbon steel substrate using atmospheric plasma spray technique. The microstructural evolution of deposited sample was investigated. Splat boundaries, micro cracks, pore morphology conversion, and grain growth mechanism were elucidated comprehensively. Results indicated a good adhesion between two different major components. No porosity formed due to mismatch between zirconia and tungsten carbide. This study pays special attention to the dependency of the microstructural characteristics to the phase distribution within the coating.
Ceramics Filler Rods Feeding for Plasma Flame Torch in Thermal Nanoparticles Spraying
Authors: Kirihara Soshu
Published: August 2022

Using nanoparticles filler rod feeding, fine coated layer can be formed successfully with higher deposition late. Nanometer sized alumina particles of 200 nm in average diameter were dispersed into liquid resins at 40 % in volume fraction. The obtained pastes were solidified through heat polymerization to crate composite rods of ᶲ4×200 mm in dimensions. The solid rods were introduced into an acetylene and oxygen gas flame torch for a coaxial direction at 5.0 mm/s in supplying speed by using a mechanical actuator. Fine coated layer of 500 µm in thickness could be formed at 100 µm/s in deposition rate on stainless steel substrates. Effective dielectric constants of these coated layers were measured to estimate porosities by time domain spectroscopic method of electromagnetic waves in a terahertz frequency range. The reducing porosities in the coated layers through the optimization of filler rods feeding speeds and nanoparticles deposition rates will be discussed.
Comparison of Simulated and Experimental Particle Mean Temperature and Velocity for Thermal Spray Coating Process
Authors: Shang S. , Batra R.C. , Cybulsky M.
Published: August 2022

We numerically solve the system of nonlinear and coupled partial differential equations expressing the conservation of mass of species, the total mass, linear momentum, and energy, the k-ε turbulence model for plasma flow, the lumped heat capacity model for particle heating, and Newton’s equations for the particle motion under pertinent initial and boundary conditions. The interaction between the powder particles and the plasma is modeled by considering the drag force the plasma exerts on the particles and vice versa. The effect of particle vaporization as well as that of turbulence modulation on the mean velocity and the mean temperature of particles is also considered. The initial-boundary-value problem has been numerically analyzed by using the recently developed software, LAVA-3DI. The computed results are found to agree well with the test observations reported in the literature.
Constrained Healing and Morphology Change Mechanism of 2D Cracks in Plasma Sprayed Thermal Barrier Coatings
Authors: Li Guang-Rong , Lei Juan , Yang Guan-Jun , Li Cheng-Xin , Li Chang-Jiu
Published: August 2022

The stiffness and thermal conductivity of thermal barrier coatings (TBCs) are inevitably changed by healing up of intersplat pores and intra-splat cracks during high temperature exposure, which results in less compliance and thermal insulating performance. However most publications on sintering of plasma sprayed TBCs are based on free-standing coatings, which ignore residual stress and the stress produced by the mismatch of thermal expansion coefficient between substrate and ceramic top coatings. In this paper, individual splat of YSZ and YSZ coatings have been sprayed on substrate of YSZ and Ni-based superalloy. Evolution of healing and morphology of 2D cracks and some properties, such as hardness and thermal conductivity, have been revealed during thermal exposure. Results showed that, during heating stage, the shear stress coming from substrate caused some tearing of bonding area tips and narrowing of inter-splat pores. Some recoverable and unrecoverable widening on intra-splat cracks occurred also due to shear stress. During annealing stage, compared with free-standing coating, the surface hardness of the coating deposited onto the Ni-based superalloy showed enhanced increasing due to the faster healing of inter-splat pores by narrowing down, and the hardness in cross-section presented retarding increasing due to the widening of cracks in out-plane direction leading to slower healing. The case of YSZ substrate fell between free-standing case and Ni-based superalloy. This would benefit the further in-depth understanding of the thermal cycling failure mechanism of plasma sprayed TBCs.
Detection and Avoidance of Unmelted Wire Pieces during Wire Arc Spraying
Authors: Eichler S. , Kirner S. , Zimmermann S. , Schein J. , Mayr W. , Zierhut J.
Published: August 2022

A real-time measuring system has been developed to record and analyze the fluctuations of burner voltage and current. The objective is to identify the occurrence of stripping unmolten wire pieces (cold shuts) and to detect corresponding spraying conditions. To identify voltage and current fluctuations causing cold shuts, high speed camera shots are synchronized with electrical measurements to analyze spraying parameters which were assumed leading to cold shuts. As a result, different cold shut conditions could be identified. The electrical cold shut identification then triggers a camera system, to capture online the size and velocity of cold shuts. Based on electrical measurements it is intended to detect wear of spraying equipment which leads to enhanced cold shuts occurrence during industrial spraying process.
Development of Thin WC-12Co Coatings Manufactured by HVOF-Spraying
Authors: Tillmann Wolfgang , Hollingsworth Peter , Baumann Ingor , Laschitzki Marcel
Published: August 2022

The thicknesses of HVOF-sprayed WC-12Co wear protective coatings usually range between 50 – 500 μm. These thicknesses ensure a homogeneous coating structure as well as sufficient material reserves for efficient wear protection. For applications which require high shape accuracies, a cost intensive finishing of the thick coatings, in terms of grinding and polishing, is necessary. Thus, smooth and thin coatings are favored. In this study, thin HVOF-sprayed carbide coatings are developed by means of fine sintered and agglomerated WC- 12Co powders (2 – 10 μm). The use of fine powders enables the reduction of the coating thickness down to values below 50 µm. To influence and adjust the thickness of the coatings the powder flow, the gun velocity and the track pitch were systematically varied. During these tests the hardness and the roughness of the coatings were scrutinized.
Effect of Type and Amount of Tungsten Carbides on the Abrasive Wear of Laser Cladded Nickel Based Coatings
Authors: Maroli Barbara , Dizdar Senad
Published: August 2022

Metal-matrix composite (MMC) coatings consisting of a nickel based metal matrix, providing toughness and tungsten carbides, providing wear resistance, are used in applications subjected to severe abrasive wear conditions. The aim of this work is to map the influence of type, morphology and amount of tungsten carbides in a nickel based matrix on the wear resistance and microstructure of laser cladded MMC coatings. Abrasive wear, evaluated according to ASTM-G65, is mainly influenced by the volume fraction of the tungsten carbides in the coating. Shape and microstructure of the tungsten carbides have a minor impact on this property, for similar degree of melting or dilution from the substrate material and size of the tungsten carbides. Microstructure analysis shows that the dissolution of the tungsten carbides in the melt pool is influenced by the chemical composition of the liquid metal phase, the microstructure and the amount of tungsten carbides selected.
Electron Microscopy and EBSD Characterization of Cold-Sprayed IN625 Coatings on 4130 Steel
Authors: Srinivasan Dheepa , Amuthan Ramar , Lau Y.C. , Chaudhuri Atanu , Raghupathy Y. , Suwas Satyam , Srivastava Chandan
Published: August 2022

The Cold spray method of material deposition is widely used for surface enhancement, to improve properties such as corrosion and wear. A detailed microstructural analysis of cold sprayed Ni based coatings (IN625 (Inconel 625 is a Trademark of Huntington alloys corporation) using the transmission electron microscope, revealed the occurrence of three distinct types of microstructures in the as sprayed condition, adjacent to each other. These include the occurrence of large (> 1 μm) grains having a high dislocation density, along with regions comprising shear bands (20-30 nm wide) and twins with a large aspect ratio (> 1000), along with locations having a very fine grained structure (20-30 nm). The crystallite size, using a Hall-Williamson plot measures an average 50 nm. The substrate deformation indicates a bilayer dynamic recrystallization, as a means to accommodate the strain. The microscopy studies will serve to correlate the bonding mechanism of cold sprayed IN625 on 4130 steel.
Epitaxial Grain Growth during 8YSZ Splat Formation on Polycrystalline YSZ Substrates by Plasma Spraying
Authors: Yang Er-Juan , Luo Xiao-Tao , Yang Guan-jun , Cheng-xin Li , Li Chang-Jiu , Takahashi Makoto
Published: August 2022

The effect of substrate template effect on the crystalline structure of plasma sprayed 8YSZ (8mol%Y2O3) splats was investigated by high resolution transmission electron microscopy (HR-TEM) examination of FIB-processed splat samples. 8YSZ splats were deposited by the atmospheric plasma spraying (APS) on the polished sintered tetragonal structure substrate (3YSZ) and cubic structure substrate (8YSZ) at different preheating temperatures. The focused ion beam (FIB) was utilized to prepared TEM cross-sectional sample of splats. The crystalline structures of both the splat and the underlying substrate were examined by HRTEM. Results showed that the 8YSZ splats deposited on the polished sintered cubic structure 8YSZ substrate at a substrate surface temperature of 900°C exhibited cubic structure and the epitaxial grain growth was confirmed between the crystalline of splat grain and immediately underlying cubic crystalline substrate grain. Moreover, epitaxial grain growth was confirmed between the crystalline of splat grain and the tetragonal structure substrate when substrate surface temperature was increased to 1200°C. The present results suggest that the crystalline structure formation of 8YSZ splats produced by plasma spraying was affected by the substrate template effect.
Experimental Investigation and Finite Element Simulation of Residual Stress Development in Thermally Sprayed Coatings
Authors: Elhoriny Mohamed , Wenzelburger Martin , Killinger Andreas , Gadow Rainer
Published: August 2022

In this study, coating buildup process of ceramic powder Al2O3 deposited on steel substrate by atmospheric plasma spraying is simulated by creating a thermo-mechanical FEA model that utilizes the element death and birth techniques in ANSYS commercial software. The simulation process starts with side-by-side deposition of coarse subparts of the ceramic layer until the entire coating is created. Simultaneously, the heat flow into the material, initial quenching stress, thermal deformation and particle impact impulse transfer are computed. The purpose is to be able to predict - for the considered spray powder and substrate material - the development of residual stresses and to assess the risk of coating failure. The model allows the prediction of heat flow, temperature profile and residual stress development over time and position in the coating and substrate. The proposed model has been successfully run and results were experimentally verified by comparing with actual residual stresses measured by the hole drilling method.
Fretting Behavior of Cold-Sprayed Cu and Cu-MoS2 Coatings
Authors: Zhang Yinyin , Chromik Richard R. , Descartes Sylvie , Regis Edouard , Vo Phuong
Published: August 2022

Cu and Cu-MoS2 coatings were fabricated by cold gas dynamic spray and the fretting wear performance of the two coatings was compared. A mixture (95 wt.% Cu + 5 wt.% MoS2) was used as feedstock for the composite coating. Coatings were sprayed with identical gas flow conditions on the substrates preheated to approximately 170°C. The cross section of the coatings was analyzed by scanning electron microscope (SEM) and MoS2 concentration was measured, as well as coating microhardness. Fretting tests were carried out under gross slip conditions in ambient environment. SEM observation on wear scars and counterspheres revealed the development of third bodies, by which the sliding was accommodated. For the Cu-MoS2 coating, solid lubrication effects in the form of friction drops occurred in early cycles (< 5k), but eventually (> 5k) the coating's friction behavior was similar to the pure Cu coating. Third body morphology and wear of the two coatings were distinctly different, which could largely be attributed to the hardness reduction of the Cu-MoS2 composite due to poorly bonded interfaces induced by the effect of MoS2 during particle impact and coating formation.