Friction performance of electroless Ni-P coatings in alkaline medium and optimization of coating parameters

AbstractThe present paper studies the friction performance of electroless Ni-P coating in alkaline medium (10% NaOH solution) and optimization of the coating process parameters is performed for minimum friction using Taguchi method based on L27 orthogonal array. The study is carried out using different combinations of four coating process parameters, namely, concentration of nickel source (A), concentration reducing agent (B), bath temperature (C) and annealing temperature (D). The friction tests are conducted with a pin-on-disk tribometer. The optimum combination of process parameters for minimum friction is obtained. Also, analysis of variance (ANOVA) is performed to find out the significant contribution of each coating process parameters and their interactions. ANOVA reveals that bath temperature has the maximum contribution in controlling the friction behaviour of Ni–P coating. The surface morphology and composition of coatings are studied with the help of scanning electron microscopy (SEM), energy dispersed X-ray (EDX) analysis and X-ray diffraction (XRD) analysis. It is found that the Ni-P coating is amorphous in as-deposited condition but gradually turns crystalline with heat treatment

Adhesive friction at the contact between rough surfaces using n-point asperity model

AbstractThe paper describes a theoretical study of adhesive friction at elastic–plastic contact of rough surfaces based on n-point asperity model. Well defined adhesion index and plasticity index are used to study the prospective situations arising out of variation in load, material properties, and surface roughness. Results are obtained for the behavior of friction force, applied load, and coefficient of friction for different combinations of adhesion index, plasticity index and mean separation of surfaces. The results obtained are in line with earlier models. It is observed that the tensile load required in maintaining a separation increases with increase in adhesion effect and extent of plastic deformation. Also coefficient of friction increases with adhesion effect

CLINICAL STUDY ON EFFICACY OF PANCHATIKTA BASTI, TILATAILADI NASYA AND AMRUTADI GUGGULU IN THE MANAGEMENT OF DIABETIC RETINOPATHY

Diabetic retinopathy (DR) is a disease of Dristipatala. Raktapitta, Dosha Avarana and Dhatukshya are the main etiological factors involved. Madhumeha is vatika type of Prameha and all the three Dosha and Saptadhatu except Asthidahtu gets vitiated. Mainly Rakta, Mamsa and Meda dhatu affected by both etiopathological mechanisms of Avarana and Dhatukshya. Agnimandya and Ama formation are initiating factors of the main disease Madhumeha and all these leads to complications similar to Raktapitta due to Rasayani daurvalya. Ojas kshaya is another etiological factor in Madhumeha. In Pranavritta vyana Vyanavayu gets obstructed by Pranavayu and leads to Indriyasunyata. Raktavritta vata too have a role in development of DR Pathology. Timir is described under Vataja nanattmaja vyadhi by Charaka. Vagbhata and Yogratnakara advised Basti chikitsa in Timir vyadhi. By considering the above facts Panchatikta Panchaprasrittika Basti was considered for this trial to reduce pathology of Sira abhisyandam and vasculopathy in diabetic retinopathy cases. Tilatailadi Yoga was considered to reduce hemorrhagic effects in retina and as Nasya is the shortest and effective route for CNS drug delivery for vision improvement, Tilatailadi Nasya was considered for this study. Amrutadi Guggulu was considered for this study, as it has anti-inflammatory, antioxidant, hypolipidemic and above all Srotosodhaka properties, which is particularly indicated for Timir vyadhi. Thus in present study an attempt has been made to prevent and check the progression of different stages of non proliferative stages of diabetic retinopathy (NPDR). Mixed results were obtained with statistically significant improvement in visual acuity, fundus signs and laboratory parameters

IMPROVING CORROSION RESISTANCE OF MAGNESIUM NANOCOMPOSITES BY USING ELECTROLESS NICKEL COATINGS

The present study aims at improving corrosion resistance of magnesium nanocomposites through autocatalytic Ni-P coating. Electroless Ni-P coatings with different concentration of sodium hypophosphite are deposited on 2% WC incorporated magnesium nanocomposites (AZ31-2WC) and the coated samples are further heat-treated. Basic characterizations and compositional analyses are done by using scanning electron microscope (SEM), energy dispersive x-ray analysis (EDAX), and X-ray diffraction analysis (XRD). Microhardness values of the developed materials are also evaluated. The attempt is made to improve corrosion resistance of AZ31-2WC by modifying surface roughness. Corrosion characteristics of Ni-P coated AZ31-2WC nanocomposites are examined by performing potentiodynamic polarization test and electrochemical impedance spectroscopy (EIS). Corrosion resistance improves with enhancement of surface quality. Corrosion resistance of AZ31-2WC nanocomposite also improves due to application of Ni-P coating. Finally, corrosion morphologies are scrutinized by SEM micrographs of corroded surface

Role of Krimi (Pathogen) in Aupasarkika Yakrit Vikara (Infective Liver diseases) - A Narrative Review

Infective liver diseases are more than 18% of total Chronic Liver Diseases and been ranked as the fifth most common cause of death worldwide. Krimi can create systemic infection like - Jvara, Vibarnata (skin rash), Shula (Pain), Bhaktadwesa (anorexia), Krimija Pandu (Anaemia) etc. to organ specific disorders like - Krimi Danta, Krimi Karna, Asadhya Pratisyaya, Krimi Granthi, Krimija Hrudroga, Krimija Shira Roga But Krimijayakrit Vikara/Roga is not found in classical literature. A considerable number of Infectious liver disease patients came to various Ayurveda Hospital and expert Ayurveda physicians either feed up with conventional treatment or cannot bear the expenses of conventional therapy. Therefore, it is an attempt to establish the role of Krimi in Aupasarkika Yakrit Vikara through reviewing Ayurveda and modern literature with some experience-based inputs. Virus, bacteria, protozoa can be Adrisya Krimi (not visible in necked eye), Anu (minute) and Suksma and Nematodes and fungus are Drisya (Visible) Krimis. Purisaja and Raktaja Krimi can produce Krimija Yakrit Roga as near to Liver and through gut - liver axis and rich circulation of liver. Jvara (Fever), Shula (abdominal pain), Mandagni (low digestive power), Pita Netrata (Jaundice) are cardinal symptom of Krimija Yakrit Roga. In three dosas, Kapha Dosa is more aggravated in Krimija Yakrit Roga. Rakta Vaha Srotas and Purisha Vaha are mostly affected Srotas in Krimija Yakrit Roga. Sahaja Krimi or Avaikarik Krimi are said to be gut microbiota which are more than 100 trillion microorganisms in the gut show high metabolic activity and are continuously helping with the host immune system through gut-liver axis. Krimija Yakrit Roga can be a type of Yakrit Roga which clinically manifested as Yakritdalludara (Hepato megaly) and Yakrit Kshyaya (Cirrhosis of Liver). Successful diagnosis of type of Krimi can be possible though careful history and appropriate microbial and radiological studies for proper treatment of liver diseases

An Emerging Solution for Detection of Phishing Attacks

In this era of computer age, as more and more people use internet to carry out their day to day work so as hackers performs various security attacks on web browsers and servers to steal user’s vital data. Now Electronic mail (E-mail) is used by everyone including organizations, agency and becoming official communication for the society as a whole in day to day basis. Even though a lot of modern techniques, tools and prevention methods are being developed to secure the users vital information but still they are prone to security attacks by the fraudsters. Phishing is one such attack and its detection with high accuracy is one of the prominent research issues in the area of cyber security. Phisher fraudulently acquire confidential information like user-id, passwords, visa card and master card details through various social engineering methods. Mostly blacklist based methodology is used for detection of phishing attacks but this method has a limitation that it cannot be used for detection of white listed phishing. This chapter aims to use machine learning algorithms to classify between phishing E-mails and genuine E-mails and helps the user in detecting attacks. The architectural model proposed in this chapter is to identify phishing and use J48 decision tree classifier to classify the fake E-mail from real E-mail. The algorithm presented here goes through several stages to identify phishing attack and helps the user in a great way to protect their vital information

TRIBO-MECHANICAL CHARACTERIZATION OF ENB ALLOY COATINGS: EFFECT OF HEAT-TREATMENT TEMPERATURE AND SODIUM BOROHYDRIDE CONCENTRATION

Previously electroless Ni-B (ENB) coatings were analyzed and optimized based on various coating parameters. However, variation of nano-indentation behaviour like nano-hardness, elastic modulus and scratch hardness variation with bath composition and heat treatment temperature has not been reported earlier. An attempt has been made to explore the same in the present study. ENB coating layers are deposited on AISI 1040 steel specimen with varying concentration of  sodium borohydride (NaBH4) and heat-treated at 350°C, 450°C and 550°C to investigate the related effects. Nano-hardness and elastic modulus of as-coated specimens are found to improve with NaBH4 concentration due to increased boron content and nodule size. Both nano-hardness and elastic modulus are observed to improve further upon heat treatment because of incorporation of various boride phases leading to compact morphology and increased size of the nodules. Scratch hardness value also increases with NaBH4 concentration and it improves further upon heat treatment and reaches to its maximum at 450°C due to presence of compact and hard Ni2B phase. Compact homogeneous surface morphology enhances the friction and wear behaviour of the heat-treated coatings even though surface roughness deteriorates after heat treatment.

Duplex electroless Ni-P/Ni-Cu-P coatings: Preparation, evaluation of microhardness, friction, wear, and corrosion performance

The current study focuses on the development of duplex Ni-P/Ni-Cu-P coatings by the electro­less deposition method. Coatings are developed on mild steel substrates with Ni-Cu-P as the outer layer and Ni-P as the inner layer and vice versa. The coated samples are heat-treated at temperatures ranging between 200 to 800 °C during 1 and 4 h. Coated samples are characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The effect of heat treatment tempera­ture and its time duration on the hardness, friction and wear behaviour of both coatings are evaluated and compared. This would help in understanding how heat treatment influences the duplex system of coatings and helps in identifying the suitable condition of heat treatment for optimal performance of the coating. It is observed that heat treatment has a positive influence over the coating performance, which is the best when treated under optimal temperature and time duration conditions. The corrosion behaviour of the coatings is also assessed with the help of electrochemical techniques, viz. potentiodynamic polari­zation and electrochemical impedance spectroscopy. The results show that the duplex coat­ings can provide substantial protection to the mild steel substrates. Heat treatment is also found to have a significant influence on the corrosion behaviour of duplex coatings

REVIEW OF ANJANA (CORRYLIUM) PROCEDURE AND ITS PROBABLE MODE OF ACTION

Shalakya Tantra is one of the eight specialties of Ashtanga Ayurveda which deals with diseases occur above the clavicle specially related to the sensory organs. Eyes hold special status among all the sense organs because good vision is crucial for social and intellectual development of human beings. Hence authentic classics prescribed several preventive and curative measures for the management of ophthalmic disorders. Among them, topical treatments are very unique, effective in the management of eye diseases and are called “Netra Kriyakalpaâ€. Netra Kriyakalpa have very fast action on the target tissues of eye. Anjana is a medicinal preparation which is applied on the lower palpebral conjunctiva or the cul-de-sac. Its active principles may be transferred to the interior of the eye according to their hydrophilicity and lipophilicity mainly through the conjunctiva and cornea by paracellular and transcelullar pathways respectively. pH, viscosity, tonicity, molecular size and molecular weight of the active ingredients are highly responsible for the absorption of Anjana. According to its form Anjana is of 3 types i.e. Gutika, Rasakriya and Churna. Gutika and Churna types of Anjana can be correlated with ophthalmic suspensions and Rasakriya type is with aqueous solutions/eye drops. Gutika and Curna Anjana have micro particles which may be deposited in the cul-de-sas and thereby increase the bioavailability to enhance ocular absorption. Anjana therapy may be highly beneficial in the anterior segment disorders because of the presence of several anatomical, biological and physiological ocular barriers. However it gives better results on the posterior segment disorders also

Pathya & Apathya (Wholesome & Unwholesome diet and regimen) in Yakrit Kshaya (Liver Cirrhosis) : A Narrative Review

Yakrit Kshaya (Liver Cirrhosis) is associated with vitiated Agni (digestive power), production of Ama (Undigested food) and Anuloma and Pratilomakshyaya (forward and backward depletion of Dhatu). Approximate 20% compensated cirrhosis patients and 65-95% decompensated cirrhosis patient have either Anuloma Dhatu Kshaya (forward depletion) or Pratilomana Dhatu Kshaya (backward depletion) or both types of malnutrition. Pathya (wholesome diet and regimen) is defined as the Ahara (Diet) and Vihara (regimen) that give proper nutrition to body and mind, clear the micro channels of Body (Pantha/Marga/Srotas), and provide happiness; that opposite is Apathya(unwholesome diet and regimen). A Pathya and Apathya chart for Yakrit Kshaya (Liver Cirrhosis) is prepared and presented. Chinta (anxiety), Shoka (depression), Krotha (anger), Duhkha (sorrow), Dukkha Shaiya (uncomforted bed) and Ratrijagarana (insomnia) can contribute for the indigestion even if a small quantity of Pathyaahara (wholesome diet). Normal diet with Goghruta (ghee) prepared from curd (Emulsified fat), Mamsa Rasa, milk can balance the protein. The Yakrit Kshaya patients should eat 6-8 times in small quantity (snax, mini meal ) as their Agni is low to very low. Mid night meal is also advisable for reduce protein breakdown. Restriction of water, sour and salty foods, fast foods are very crucial for the treatment outcome as it create Ama. More research on Pathya (Ayurveda diet) in Yakritkshaya (Liver cirrhosis) is encouraged