A Single Server Retrial Queue with Impatient Customers

In the present paper, a single server retrial queue with impatient customers is studied. The primary arrivals and repeating calls follow the Poisson distribution. The service time is exponentially distributed. Explicit time-dependent probabilities of an exact number of arrivals and departures from the orbit are obtained by solving the differential-difference equations recursively. Steady state solution of the number of busy servers is obtained. The numerical results are graphically displayed to illustrate the effect of arrival rate, retrial rate and service rate on different probabilities against time. Some special cases of interest are also deduced

In Vitro Anti Microbial Activity of Roylea elegans, Chrozophora tinctoria, and Daphniphyllum himalaense

Herbal combination plays a major role in enhancing the activity due to its synergetic effects. Many well-known plants possess their antibacterial activity individually, and a combination of these may lead to the better efficacy of results. Plants belonging to the family Euphorbiaceae and Laminaceae possess an excellent antibacterial effect against various bacteria. However, secondary metabolites like; terpenes, alkaloids, and phenolic compounds are well for their free radical scavenging activity, which may inhibit the growth of microorganisms. Thus, the combination of these herbal plants is evaluated for antibacterial activity using hydrogel forms solution

Factors Influencing Restaurant Selection In The Covid-19 Era: A Study Of Consumer Preferences In India

COVID-19 struck the humanity at the end of 2019 and since then it has been ravaging the mankind. Since then the economies have been badly affected; businesses have shut down and the restaurant businesses are no exception to it. Now, when the vaccination programs are being carried out by the governments all around the world, including India, and restrictions are going away, the customers will be coming out to the restaurants. This paper intends to study what are the factors which will make the Indian customers choose a restaurant and to find out if there have been effects of the pandemic on the criteria of restaurant selection. To find the answers to these, a questionnaire with ten various factors was designed and circulated by using Google Form. The data thus collected was analyzed by applying one sample t-test and Gap analysis. The hypothesis was tested and it was found that the pandemic had an impact on the restaurant selection criterion. ‘Personal hygiene of the staff’, ‘quality of food ingredients’ and ‘taste of food’ are the most important factors for customers in deciding to choose a restaurant and ‘location’ with no impact on restaurant selection

Modeling and optimization of process variables of wire-cut electric discharge machining of super alloy Udimet-L605

AbstractThis paper presents the behavior of Udimet-L605 after wire electric discharge machining and evaluating the WEDM process using sophisticated machine learning approaches. The experimental work is depicted on the basis of Taguchi orthogonal L27 array, considering six input variables and three interactions. Three models such as support vector machine algorithms based on PUK kernel, non-linear regression and multi-linear regression have been proposed to examine the variance between experimental and predicted outcome and preferred the preeminent model based on its evaluation parameters performance and graph analysis. The grey relational analysis is the relevant approach to obtain the best grouping of input variables for maximum material removal rate and minimum surface roughness. Based on statistical analysis, it has been concluded that pulse-on time, interaction between pulse-on time x pulse-off time, spark-gap voltage and wire tension are the momentous variable for surface roughness while the pulse-on time, spark-gap voltage and pulse-off time are the momentous variables for material removal rate. The micro structural and compositional changes on the surface of work material were examined by means of SEM and EDX analysis. The thickness of the white layer and the recast layer formation increases with increases in the pulse-on time duration

Effect of Adhesion Promoter on Bond Strength of Reconditioned Brackets – an In vitro Study

Objectives: To compare the shear bond strength of recycled orthodontic metal brackets using an adhesion booster and conventional primer and using the Adhesive Remnant Index (ARI) score to assess the site of debonding. Materials and Methods: Eighty premolar teeth were randomly divided into 3 groups of 20 teeth each: Group A-New brackets and Transbond XT, Group B-Recycled brackets and Transbond XT, Group C-Recycled brackets and Transbond XT + Enhance LC. Brackets were recycled using sandblaster. Bond strength was tested on a universal testing machine and remnant adhesive on the tooth surface was determined. Kruskal Wallis test and Mann Whitney test were carried out to know the significant difference between the groups. Chi – square test was used to determine significant differences in the ARI (Adhesive Remnant Index) scores. Results: Highest mean load was recorded in Group A (9.58±1.72 MPa), followed by Group C (8.60±2.05 MPa) and Group B (6.39±1.64 MPa). Chi- square test indicated significant differences (P=.002) in ARI scores. Group A and Group C were associated significantly for score 2 of ARI; Group B for Score 0 of ARI. Conclusion: The bond strength of recycled orthodontic brackets with Transbond XT was significantly lower when compared to bond strength of recycled brackets with an adhesion booster. After recycling the brackets with sandblaster and using an adhesion booster, the previously debonded brackets gave the bond strength comparable to new brackets with Transbond XT. The ARI data showed statistically significant association between the ARI scores and the groups

Effect of denture wearing on occurrence of fungal isolates in the oral cavity: a pilot study

Objectives: An attempt was made to evaluate effect of denture wearing on occurrence of fungal isolates in the oral cavity before and after complete denture insertion. Method: Twenty five completely edentulous patients were selected; swab samples were collected intraorally before fabrication of complete dentures from labial vestibular area and after complete denture fabrication (one and four days after denture insertion). Further these samples were inoculated and incubated. Results: In nineteen patients no isolate of fungus before denture insertion as well as 4 days after denture insertion was found. In two subject results were false positive (contamination from environment), and in four patients there was increase in growth but not much significant increase of growth of fungal isolates was seen (mild growth of fungus only after denture insertion). One of the major finding of this study was overall occurrence of fungal isolates (before and after denture insertion) in the oral cavity were not significant

Reimplantation: clinical Implications and outcome of dry storage of avulsed teeth

Reimplantation refers to the insertion and temporary fixation of completely or partially avulsed teeth that have resulted from traumatic injury. Reimplantation of an avulsed tooth depends on certain clinical conditions like phy- siological status of periodontal ligament (PDL), the stage of root development and the length of extra oral time. Depending on the patient’s age, retention of the permanent incisor can maintain the aesthetic appearance, occlusal function and alveolar ridge height. Though the risk of progressive replacement resorption and subsequent tooth loss is high after a long dry storage, reimplantation makes a provision for an aesthetically acceptable permanent prosthesis at a later age. This article presents management of two cases with avulsed permanent incisors that were stored in dry conditions for seven hours and three days respectivel

Amelogenesis Imperfecta -Etiology and Prosthodontic Management

Amelogenesis imperfecta represents a variety of structural abnormalities of enamel that result from some malfunction of the enamel organ. The aim of the treatment is to restore esthetics,masticatory function, increase vertical dimension of occlusion and  reduce  hypersensitivity of teeth. Modern  methods and materials have widened the range of available treatment

Acute colonic pseudo-obstruction (ogilvie’s syndrome) or colonic perforation: A rare complication following cesarean section

Ogilvie’s syndrome or pseudo-obstruction of the colon shows up as a clinical picture of acute obstruction of the large bowel without an associated pathological lesion as usually occurs in older patients. Here, we report a case series of three cases of Ogilvie’s syndrome following caesarean section. The caesarean section seems to be the most common operative procedure associated with this syndrome. The diagnosis was made by plain X-ray of the patient’s abdomen, which revealed dilated gut loops or air under the diaphragm in case of perforation. The pathological cause seems to be the disturbance of the autonomic innervation of the colon. The colon should be decompressed rapidly using colonoscopy. Surgery should be reserved for cases that have complications or that have been refractory to conservative treatment. Of our three cases, one was treated successfully by colonoscopic decompression and IV neostigmine, whereas, rest two patients presented late with colonic perforation. So they were immediately taken for exploratory laparotomy

A rare case of leiomyosarcoma of cervix and challenges in its management: a case report and brief review of literature

Leiomyosarcoma of cervix is an aggressive and rare tumour of the cervix with poor prognosis. Management plan differs greatly from other common cervical malignancies. A 38 year old multiparous lady presented with a large circumferential cervical tumour which was diagnosed as leiomyosarcoma of cervix on cervical biopsy. It was a surgical challenge. Patient underwent pre-operative ureteric stenting followed by exploratory laparotomy with hysterectomy with bilateral salphingo-oophorectomy. Surgical difficulties were encountered due to deep impaction of tumour in pelvis and altered anatomy due to the bulk of tumour. Retrograde approach was taken and pouch of Douglas was opened before clamping the mackenrodts and the uterus was bisected and debulking of tumour done simultaneously to facilitate the surgery. Post operatively patient received chemotherapy (Vincristine, adriamycin andcyclophosphamide) followed by radiotherapy. Patient developed vesicovaginal fistula and liver metastasis nine months post- surgery. She received second line of chemotherapy (gemcitabine and docetaxel) after which she was lost to follow up.