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The purpose of this paper is to introduce the notion of set-valued (𝛼, 𝑝)- weak contractions in cone metric spaces over Banach algebra and to prove some fixed point theorems for such mappings. The fixed point results of this paper generalize and extend several known fixed point results on cone metric spaces. An example in support of our results is given.

In this work, we introduce the class of ordered weak \varphi-contractions in cone metric spaces over Banach algebras and prove some fixed point results for the mappings belonging to this new class. Our results generalize and extend some known fixed point results in cone metric spaces to the spaces equipped with a partial order. Some examples are given which illustrate the results proved herein.

Introduction: The aim and objective of this study was to predict difficulty in endotracheal intubation by employing various bed side screening tests in patients posted for surgeries under general anaesthesia. Various bedside tests were used individually and in combination to assess the sensitivity and specificity in order to determine their positive predictive value and negative predictive value. Materials and Methods: The preoperative airway assessment was conducted using multiple screening tests like interincisor gap, thyromental distance, modified mallampati test, sternomental distance and head and neck movement. Intubation was considered difficult if the view on the laryngoscopy was Cormack and lehane grade III or IV, three or more attempts at tracheal intubation, duration >10 min or if special maneuvers were required to facilitate intubation. The results were evaluated on the basis of sensitivity, specificity, positive and negative predictive values of these tests. Results: The sternomental distance test has the highest sensitivity and positive predictive value of 77.3% and 63.0% and negative predictive value of 93.2% resulting as the best individual test for predicting difficulty for intubation followed by mallampati test with sensitivity of 60.0% and negative predictive value of 92.7%. IIG + MMT + SMD combination resulted best with sensitivity, specificity, PPV and NPV of 98.8%, 26.7%, 88.4% and 80.0% respectively. Conclusion: When multiple predictors were taken into consideration there was a considerable reduction in the outcome of false positives and false negatives with significant improvement in sensitivity, positive predictive value and negative predictive value. The application of multiple predictors can reduce the frequency of unanticipated difficulty and unnecessary interventions related to over- prediction of airway difficulty. Keywords: Interincisor gap, Thyromental distance, Modified mallampati test, Sternomental distance, Head and neck movem

In critically ill patients in Intensive Care Unit (ICU), patency of airway and managementof difficult airway are of utmost importance. The incidence of difficult intubation maybe 10% to 22% depending on the various factors in patient as well as availability ofequipment facilities. As compared to the regular surgery in operation theatre, themanagement of airway in critically ill patients is considerably different and morechallenging. The physiological reserve and co-morbidities are more common in criticallyill patients. In ICU, recent techniques of airway management must be considered andpracticed, such as videolaryngoscope (VLS), fiberoptic bronchoscope and supraglotticdevices. The success for airway management would be greater if airway expert, therequired devices and an adequate protocol are available. The outcome of managingairway would be enhanced if best use of available airway devices in a particular hospitalsetup since every instrument may not be available. The standard guidelines for difficultairway and the protocol of individual hospital may reduce the complications; hencemust be followed. The availability of difficult airway cart and capnograph is a must. Theindications and timing of surgical airway must be clear to the airway team. The Trainingcourses for the staff in ICU should be held regularly to apprise them of advancementin airway management. The best use of available airway equipment should be made incritically ill patients. At least, one airway expert must be accessible in ICU at any giventime. Received: 12 Sep 2018Reviewed: 5 Oct 2018Accepted: 10 Oct 2018 Citation: Malhotra SK, Gandhi K. Airway management in critically sick in intensive care. Anaesth Pain & Intensive Care 2018;22 Suppl 1:S21-S28

Perennial fruits crops by the virtue of their nutritional qualities have already emerged as a major alternative, cutting short the menacing load on the consumption of traditional monotonous cereal/...

Background and Aims: The external jugular vein (EJV), often used for resuscitation, has been underutilised for central venous catheterisation (CVC) in view of an unpredictable success rate. There is an encouraging literature on the improved success rate of CVC through EJV with the inclusion of certain body manoeuvres. This prospective randomised controlled study was conducted with the aim of evaluating the efficacy of body manoeuvres in improving the success rate of CVC through EJV. Methods: One hundred patients aged 18–50 years, scheduled for elective surgery requiring CVC, were randomly assigned to either undergo CVC using Seldinger technique with body manoeuvres or a control group undergoing CVC without body manoeuvres. The primary outcome was the success rate of CVC, as observed in the post-procedure chest radiograph. Secondary outcomes included quality of central venous pressure waveform, catheterisation attempts, total time for CVC, complications. Results: CVC was achieved in 98% (49/50) of patients in study group and 80% (40/50) of patients in control group (P = 0.008). Mean catheterisation time was significantly lower in the study group (151.06 ± 40.50 s) compared to control group (173.50 ± 50.66 s) (P = 0.023). The incidence of catheter misplacement and failure to cannulate were lower in the study group (0%, 2% vs. 20%, 12.5%, respectively). Groups did not differ in a number of catheterisation attempts and incidence of haematoma. Conclusion: Inclusion of various body manoeuvres to Seldinger technique significantly improves the success rate of CVC through EJV.

The current available literature is not unanimous in reporting the utility of short-axis and long-axis techniques for radial artery cannulation in both adults and children. This study was designed to compare short-axis out-of-plane (SA-OOP) and long-axis in-plane (LA-IP) techniques in ultrasound-guided radial artery cannulation in adults. In this prospective randomized controlled trial, 150 adult patients of American Society of Anesthesiologists physical status I–III aged between 18 and 70 years were included. All patients were randomized into two groups (group SA-OOP) and (group LA-IP) of 75 each undergoing ultrasound-guided radial artery cannulation. The primary outcome was successful cannulation in the first attempt. Secondary outcomes included antero-posterior arterial diameter, skin-to-artery distance, ultrasonic localization time, cannulation time, no of attempts to cannulate artery, cannula insertion failure, and vascular complications. First-attempt arterial cannulation was successful in 80 % of patients in the SA-OOP group as opposed to 82.6 % patients in the LA-IP group (p = 0.67). The time to cannulate the artery was similar between the two groups, but the time to localize artery was significantly higher in the long-axis technique (p

Background and Aims: Most vital aspect of Endoscopic Sinus Surgery (ESS) is an optimal visibility in the surgical field. This invariably requires controlled hypotension to facilitate surgical dissection and to decrease operative time. We used esmolol and magnesium sulfate to achieve controlled hypotension and assessed the quality of the surgical field in ESS. Material and Methods: A total of 30 patients undergoing ESS, were enrolled in three parallel groups of 10 patients each in a prospective randomized double-blind study. “Magnesium Sulfate group” received magnesium sulfate 40 mg/kg intravenously (i.v.) as a bolus over 10 min before induction of anesthesia, followed by 15-30 mg/kg/h through infusion. “Esmolol group” received 0.5 mg/kg i.v. bolus over 10 min after induction followed by 150-300 μg/kg/min infusion and “control group” received normal saline in same volume schedule. The primary aim was to assess the quality of surgical field, using Fromme scale. Category Scale values of all the three groups were compared using Kruskal-Wallis analysis of variance (ANOVA) test. Hemodynamic data was compared using ANOVA test. Results: Quality of the surgical field was better in both magnesium sulfate and esmolol groups as compared to the control group. Durations of anesthesia and surgery were significantly lower in esmolol group as compared to the control group. Blood loss was comparable in all the three groups. Conclusion: Quality of the surgical field was better in esmolol and magnesium sulfate groups as compared to control group. Duration of surgery was significantly less in esmolol group as compared to other two groups.

In this work, we introduce the notion of relation-theoretic contractions in cone metric spaces with Banach algebra and prove some fixed point results for such contractions. Our results generalize and unify several known results in the setting of cone metric spaces with Banach algebra. An example is provided which illustrate the results proved herein and shows that how the new results are different from existing ones.

Leprosy is a medical - social disease, it is associated with stigma in the society due to the resulting deformities in some persons. Although stigma has decreased after the widespread use of MDT, some disabilities do occur which are mostly due to late initiation of treatment and inappropriate care. Besides the nerve and skin involvement bone changes have been reported to be common in leprosy. These bony changes need to be understood in the present MDT era specially in the context of clinical spectrum and duration of disease/ deformities. Fifty clinically diagnosed and histologically classified leprosy patients with deformities/ disabilities of either hands/feet/face who attended the OPD of Department of Dermatology, Venereology and Leprosy, Government Medical College, Amritsar were examined and evaluated in the study. Radiological examination of hands, feet and skull was done in each case and the bone changes in hands and feet; and skull and paranasal sinus changes were correlated with clinical parameters. Bone changes were observed in 90% of cases radiologically. Specific bone changes in hands and feet, non-specific bone changes in hands, feet, skull and paranasal sinuses were seen in 66%, 82% and 32% of cases respectively. Common specific bone changes in hands and feet observed were primary periostitis (14%), honey combing (46%), bone cyst (36%), thinning and irregularity of cortex (28%) and area of bone destruction (20%); Among the non-specific bone changes observed were contracted fingers/claw hands/claw toes (64%) and absorption of terminal phalanges (40%). The maxillary sinus, and paranasal sinus changes were the most common radiological findings observed in skull. The study of the radiological changes may help the clinicians to understand the gravity of the situation and undertake steps for timely prevention of permanent loss of function and the occurrence of deformities and disabilities.

Sleep deprivation is one of the various stress factors which may affect the efficiency of an anaesthitist. Cognitive functions play a vital role in safe anaesthetic practice. To assess the effect of sleep deprivation on cognitive functions, forty anaesthesia residents were tested using various tests in two planned situations. 'Situation I' comprised of non sleep deprived state and 'Situation II' was the sleep deprived state defined as 'less than 4 hours of sleep in the last 24 hours'. The tests used were Trail making task, Digit symbol test, Letter comparison test and Standard progressive matrices. There was a statistically significant decrease in the performance scores after sleep deprivation. It is concluded that acute sleep deprivation adversely affects cognitive functions.

Study Objective: Various randomized controlled trials and a meta-analysis have compared i-gel™ and laryngeal mask airway Supreme™ (LMA-S™) in adult patients and found that both the devices provided equivalent oropharyngeal leak pressure (OLP). However, no randomized controlled trial has compared air-Q™ with i-gel™ and LMA-S™ in adult patient. Hence, we designed this study to compare air-Q™ with LMA-S™ and i-gel™ in adult patients. Materials and Methods: A total of 75 adult patients of the American Society of Anesthesiologists physical status I/II of both sexes, between 18 and 60 years, were included in this prospective randomized controlled trial conducted in a tertiary care center. Randomization of patients was done in three equal groups according to the insertion of supraglottic airway device by a computer-generated random number sequence: group air-Q™ (n = 25), group i-gel™ (n = 25), and group LMA-S™ (n = 25). Primary outcome of this study was OLP. We also recorded time for successful placement of device, ease of device insertion, number of attempts to insert device, and ease of gastric tube insertion along with postoperative complications. Results: The mean ± standard deviation OLP of air-Q™, i-gel™, and LMA-S™ was 26.13 ± 4.957 cm, 23.75 ± 5.439 cm, and 24.80 ± 4.78 cm H2O (P = 0.279). The first insertion success rate for air-Q™, i-gel™, and LMA-S™ was 80%, 76%, and 92%, respectively (P = 0.353). The insertion time of air-Q™, i-gel™, and LMA-S™ was 20.6 ± 4.4, 14.8 ± 5.4, and 15.2 ± 4.7 s, respectively (P = 0.000). Time taken for air-Q™ insertion was significantly higher than time taken for i-gel™ (mean difference 5.8 s, P < 0.0001) and LMA-S™ (mean difference 5.4 s, P = 0.0001) insertion. Postoperative complications were similar with all three devices. Conclusions: We concluded that air-Q™, i-gel™, and LMA-S™ were equally efficacious in terms of routine airway management in adult patients with normal airway anatomy.

Coconut (Cocos nucifera L.) is an important perennial plantation crop and to improve the productivity, the innate soil constraints should be ameliorated. The red, lateritic and sandy coconut soils are suffering with soil acidity, low CEC and poor nutrient reserve. A study on nutrient removal by coconut provides guidelines for the fertilizer input required. The effect of soil nutrient imbalance on the availability of nutrients emphasize the need based balanced fertilizer supply to coconut soils. The built up of soil available P in acidic red soils under continuous phosphatic fertilizer application strengthens the need to realize the soil test based fertilizer application. The potassium supply in the acid soils is poor, coconut being a huge feeder of potassium needs constant supply of potassium. Secondary and micronutrient deficiencies are emerging as potential yield limiting nutrients for coconut. Biomass recycling studies under coconut based cropping systems shows promising results in achieving the nutrient supply with the available biomass recycling through vermicompost. Minimizing the biomass exported out of farm especially coconut husk may improve potassium supply to palms through organic farming. Microbial studies showed that biomass recycling improved the beneficial microorganism in the rhizosphere and thereby enhances the nutrient availability. Fertigation technique showed higher nutrient use efficiency, soil and water conservation measures improved the yield of coconut in sandy soil and checks the losses through run-off and erosion in sloppy soils. Site specific soil management strategies can improve the coconut yield in an eco-friendly way.

This study was carried out to investigate morpho-physiological and productivity characteristics of four genotypes of five years old guava (Psidium guajava L.) trees, grown under hot-arid zone of Rajasthan. Preliminary investigation indicated that all four cultivars of guava could survive except merely 10.0% field mortality in guava cv. L-49. The maximum increase in plant height (25.93%) and number of new leaves/branch (4.66) over six months of planting were recorded in Sweta, followed by Lalit, while during fruiting (August for rainy season guava) highest number of new shoot sprouts/branch was found in Allahabad Safeda, followed by Sweta. Lalit and Sweta also produced substantial number of new leaves/branch during fruiting, than the other cultivars. Chlorophyll a (Chla), chlorophyll b (Chlb) and total chlorophyll (Chltotal) contents were highest in L-49, followed by Lalit. The leaves produced on Sweta received lesser photosynthetically active radiations (PAR) but had highest leaf area (80.91 cm2), specific leaf area (SLA; 36.61 cm2/g) and relative water content (RWC; 60.19%). Although L-49 had thicker leaves (lowest SLA; 33. 29 cm2/g), indicating better adaptation towards resource poor environment but other cultivars of guava also had SLA at par among other three cultivars. Allahabad Safeda received maximum PAR (1066 μE/m2/s), also had highest internal CO2 concentration (Ci; 207.76 μmol/mol), while highest net photosynthesis rate (PN; 10.84 μmol CO2/m2/s), carboxylation efficiency (CE) and water use efficiency (WUE) were observed in Lalit. Guava cv. L-49, however, showed lowest PN (6.31 μmol C02/m2/s), Ci, WUE, transpiration rate (E) and CE. Thus, guava cultivars Sweta followed by Lalit performed better under hot-arid environment with better growth and physiological adaptation. L-49 was not found suitable for the area.

In this paper we present stress modeling and mechanical response of set cement sheath in cased wellbore to quantify induced stresses and design of suitable elastic cement system. Many cement systems with latex, Graphite & fiber material have been tested for mechanical properties (Compressive strength, Tensile strength, Poison's ratio and Young's Modulus) and results are evaluated by stress calculations. Stress model calculation matches with previous paper results in this line. Cement mixing is done as per API RP10B2 and cured in molds at 115°C for 72 hours under 3000 psi. Compressive strength was measured on UCS testing machine. Brazillian method has been adopted for evaluating tensile strength of set cement. Sonic wave velocity method used for evaluation of Poison ratio and Young's modulus. Loss of cement bond behind casing due to variation in wellbore pressure during Hydro-Fracturing and casing integrity testing has been observed in several wells. Stresses induced in the cement sheath due to variation of wellbore pressure are the cause of this damage. It has been observed that cement sheath being weaker in tensile strength, often fails due to tensile stresses. Results show that tensile strength is near about 1/10th of compressive strength in Portland cement which supports previous studies in this field. However this ratio is not fixed for all kind of cement system. Stresses developed in set cement system has been calculated by feeding mechanical properties in stress modeling. Based on induced stresses, a safe limit of pressure variation has been determined for many cement system. Hence out of many cement design, suitable cement design can be chosen for a particular wellbore condition. However prediction of wellbore pressure during Hydro-Fracturing and casing integrity testing is necessary in this case. The outcomes indicate that the elastic properties (Poison's Ratio and Young's Modulus) of the casing, cement, and formation play a significant role. Results show that for high pressure variation, cement system with better elastic properties are preferred over compressive strength. Stress calculation methodology helps to optimize the cement system to withstand high pressure during testing and Hydro-fracturing of well. Many cement system with improved elastic properties are tabulated and can be utilized in as per the suitability of wellbore condition.

Venous air embolism is a serious life-threatening situation that is common in surgical procedures performed in traditional sitting position, such as posterior fossa surgery. Anesthesiologist has the responsibility of managing such patients, right from evaluation to positioning, monitoring, prevention of venous air embolism, and safeguarding the neurological status. There should be awareness regarding this hazardous problem that may occur during neurosurgical procedures. The aim of monitoring is the timely detection of venous air embolism and to keep the patient hemodynamically stable. There is a scarcity of prospective, controlled trials in the literature regarding the prevention and management strategies. High-risk patients undergoing complicating neurological procedures must be monitored using Doppler ultrasound and ETCO2 monitoring. To prevent venous air embolism, the patient must be kept hydrated, safely positioned, and adequately monitored to detect air embolism early and manage the hemodynamic problems diligently. In the presence of coexisting diseases, monitors such as TEE and central venous catheterization should be employed. Hyperbaric oxygen may be considered depending on the duration and degree of embolic phenomenon and feasibility of its use. Dynamic clinical and basic investigations would improve the measures to deal with this situation in a most favorable manner.

In this paper, we introduce a modified Ishikawa iteration for a countable family of multi-valued mappings. We use the best approximation operator to obtain weak and strong convergence theorems in a Banach space. We apply the main results to the problem of finding a common fixed point of a countable family of I-Nonexpansive multi-valued mappings.

Out of all the brain tumors, 10% are pituitary tumors. Surgical interventions in this field have advanced and so have techniques of anesthesia and intensive care. Presenting features of the patients with pituitary tumors are often due to excessive or decreased secretion of hormones. Most commonly performed procedure is transsphenoidal pituitary surgery which requires skillful anesthetic technique as a number of associated comorbidities may exist. For a positive surgical result, a team consisting of endocrine surgeon, endocrinologist, neurosurgeon and anesthesiologist is a must. An emphasis is required on preoperative evaluation of airway, endocrinal and neurological status. The understanding of pathophysiology, perioperative anesthetic management, awareness of likely complications and postoperative care, results in successful outcome. How to cite this article Malhotra SK, Sharma K, Saini V. Pituitary Surgery and Anesthetic Management: An Update. World J Endoc Surg 2013;5(1):1-5.

Elective temporary clipping (ETC) is increasingly used in surgery for aneurysms. This study was to assess whether the impact of ETC on intraoperative aneurysmal rupture (IAR) translates into neurological outcome. Patients who underwent surgery for ruptured anterior circulation aneurysms were prospectively studied for various factors related to ETC, IAR and neurological outcome at 3 months. Univariate and multivariate analyses were performed using SPSS20. Of the total 273 ruptured aneurysm surgeries studied, IAR was observed in only six out of 132 aneurysms (4.5 %) who had ETC, compared with 78 out of 141 (55.3 %) without ETC (p

Effect of cryogenic grinding on recovery of volatile oil, fatty oil percentage and their constituents in two cumin (Cuminum cyminum L.) genotypes have been analyzed. Cryogenic grinding not only retains the volatiles but enhanced the recovery by 33.9 % in GC 4 and 43.5 % in RZ 209. A significant increase (29.9 %) over normal grinding in oil percentage was also observed in genotype RZ 209. This increase was, however, less (15.4 %) in genotype GC 4. Nineteen major compounds were identified in the essential oil of both genotypes. The two grinding techniques had significant effects on dependent variables, viz., volatile oil and monoterpenes. Cuminaldehyde was the main constituent in both genotypes, content of which increased from 48.2 to 56.1 % in GC 4 on cryo grinding. Content of terpines were found to decrease in cryo ground samples of GC 4 and either decrease or no change was found in RZ 209. Organoleptic test showed more pleasant aroma in cryo ground seeds of both the genotypes. Significant increase was also reported in fatty oil yield due to cryogenic grinding. Fatty acid methyl ester (FAME) analysis showed oleic acid as major FAME content of which increased from 88.1 to 94.9 % in RZ 209 and from 88.2 to 90.1 % in GC 4 on cryogenic grinding. Other prominent FAME were palmitic, palmitoleic and stearic acid. Results indicated commercial potential of cryogenic grinding technology for cumin in general and spices in particular for better retention of flavour and quality in spices.

Public databases contain large datasets of plant expressed sequence tags (ESTs) that can be used for mining microsatellite/simple sequence repeat markers. The identification and annotation of these markers take considerable time. Here, we describe an efficient, high-throughput microsatellite mining, and analysis pipeline, standalone EST microsatellite mining and analysis tool (SEMAT). The pipeline bundles sequence trimming, assembly, microsatellite identification, primer selection, and blast annotation, for which it consecutively uses SeqClean, CAP3, MISA, Primer3, and Blast. SEMAT is written using Perl scripts, and it runs under Ubuntu and Fedora Linux. SEMAT is an efficient and time-saving bioinformatics tool to accomplish the high throughput EST-SSR analysis. It is freely available from http://semat.cpcribioinformatics.in/ .

Thin walled tubes are used as energy absorbing elements in automobile applications. The circular tube proves to be a popular energy absorber because it provides a reasonably constant operating force which is the prime characteristics of the energy absorber. Square and rectangular tubes are widely used in automobile structures as these cross sections are suitable for welding with other components in the structure and hence highly preferred. Advanced high strength steels can be utilised to absorb crash energy and minimise intrusion in the occupant zone. In this work circular, square and rectangular tubes made up of dual phase steel are tested in static and dynamic conditions. All the tubes are subjected to same amount of input impact energy but the specific energy absorption is higher in circular steel tubes. The results are compared with those for annealed tubes of same cross section. The effect of impact velocity is also studied by keeping the impact mass constant and varying the drop height. The experimental results are compared with the theoretical results and good agreement is found.

Transhiatal esophagectomy (THE) is a common operative procedure for carcinoma esophagus. Complications of this procedure include arrhythmias and hypotension during blunt dissection of the esophagus from posterior mediastinum. In the literature, exact incidence and type of arrhythmias have not been reported. We employed Holter monitoring during mediastinal manipulation in patients undergoing THE, for this purpose.This prospective study was carried out in 20 consecutive American Society of Anesthesiologists grade I-II patients undergoing THE. Anesthetic technique included induction with thiopentone and maintenance with morphine, vecuronium, and isoflurane. In addition to routine parameters, Holter monitoring was undertaken to record the exact incidence and types of arrhythmias. "Premanipulation" or control period included duration of 30 minutes preceding mediastinal manipulation, while "during manipulation" or study period included the duration of mediastinal manipulation. The incidence of arrhythmias was studied for 48 hours in the postoperative period. The Fisher exact test was applied to analyze incidence of arrhythmias and hypotension.Out of 20 patients, only 2 had arrhythmias in the premanipulation period, while 13 had arrhythmias during the manipulation period (p0.01). During the manipulation period, arrhythmias included supraventricular ectopics and ventricular ectopics in 2 patients each and a combination of both in 9 patients. Arrhythmias were transient and had no correlation with either duration or degree of hypotension in all the patients. However, there was a linear relationship between hypotension and duration of mediastinal manipulation. Two patients (10%) had atrial arrhythmias in the postoperative period.In transhiatal esophagectomy, there is a significant incidence of both arrhythmias and hypotension during mediastinal manipulation. The incidence of arrhythmias can be minimized by limiting the duration of the manipulation. The incidence of postoperative arrhythmias was not significant.

Drilling is a frequently practiced machining process for fiber-reinforced plastics (FRP) in industry owing to the need for component assembly in mechanical structures. Drilling experiments are performed on a (0/45/90) 2s 3-mm-thick glass fiber-reinforced laminate using 4-, 6- and 8-mm-diameter HSS drills. The machining response of the quasi-isotropic laminate was studied by monitoring the thrust and torque. The performance of the HSS drills for different cutting conditions was studied by measuring the tool wear. Delamination due to drilling is a major concern in machining a composite laminate and is analyzed by using linear elastic fracture mechanics, classical plate bending theory, and the mechanics of composites. A mechanical model for evaluating the critical thrust at which delamination is initiated at different ply locations has been used, and the critical thrust force at the onset of delamination has been found to be 70 N. The present work analyzes data on the thrust force, torque, and tool life by using a group method data handling (GMDH) algorithm. An optimization algorithm using simulated annealing with a performance index is then applied to search for the optimal process parameters for delaminatien constrained drilling.

The dynamic and static mechanical properties of randomly oriented intimately mixed short banana/sisal hybrid fibre reinforced polyester composites were determined. Dynamic properties such as the storage modulus (E′), damping behaviour (tan δ) and static mechanical properties such as tensile, flexural and impact properties were investigated as a function of total fibre volume fraction and the relative volume fraction of the two fibres. Keeping the relative volume fraction of banana and sisal (1:1), the volume fraction of the fibre was optimised. The storage modulus was found to increase with fibre volume fraction above glass transition temperature (Tg) of the matrix and maximum value was obtained at a volume fraction (Vf) of 0.40. The tan δ peak height was minimum and peak width was maximum at 0.40Vf. Tensile modulus and flexural strength were found to be the highest at 0.40 volume fraction, which indicates effective stress transfer between the fibre and matrix. A positive shift in Tg of polyester matrix at 0.40Vf also indicates better fibre/matrix interaction. Keeping the total fibre volume fraction, 0.40Vf, hybrid composites having different volume ratios of the fibres and unhybridised composites were prepared and analysed. Sisal/polyester composite showed maximum damping behaviour and highest impact strength as compared to banana/polyester as well as hybrid composites. However, maximum stress transfer between the fibre and matrix was obtained in composites having volume ratio of banana and sisal as 3:1,which has lowest tan δ value and highest E′ value at Tg. The tensile strength and flexural modulus were also the maximum and impact strength was the minimum at this volume ratio. Fractographic evaluations carried out under scanning electron microscope (SEM) confirm the quantitative characterisation obtained from static and dynamic mechanical analysis. The Arrhenius relationship has been used to calculate the activation energy of the glass transition of the polyester. The highest activation energy was found in hybrid composite with volume ratio of banana and sisal as 3:1. A master curve was constructed based on time–temperature superposition principle. Finally, the experimental results were compared with theoretical predictions.

Dynamic mechanical test methods have been widely employed for investigating the structures and viscoelastic behavior of polymeric materials to determine their relevant stiffness and damping characteristics for various applications. Randomly oriented short banana/sisal hybrid fiber–reinforced polyester composites were prepared by keeping the volume ratio of banana and sisal 1 : 1 and the total fiber loading 0.40 volume fraction. Bilayer (banana/sisal), trilayer (banana/sisal/banana and sisal/banana/sisal), and intimate mix composites were prepared. The effect of layering pattern on storage modulus (E′), damping behavior (tan δ), and loss modulus (E″) was studied as a function of temperature and frequency. Bilayer composite showed high damping property while intimately mixed and banana/sisal/banana composites showed increased stiffness compared to the other pattern. The Arrhenius relationship has been used to calculate the activation energy of the glass transition of the composites. The activation energy of the intimately mixed composite was found to be the highest. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2168–2174, 2005

Cocoa (Theobroma cacao L.) is an important plantation crop adapted as a mixed crop in palm based cropping systems of India which effectively utilised the land, air and root space. Four decades of cocoa research paved way for identification of potential clones and development of varieties suitable for different agro climatic conditions and tolerant to both biotic and abiotic stresses. The achievements are well recognised by International cocoa research communities especially in the Asia Pacific region which is mainly on coconut based cropping models. The challenges of management of genetic resources in the introduced environment coupled with long term breeding strategies resulted in positive achievements to take Indian cocoa to satisfy the requirement of chocolate industries. Supply of quality planting material of elite clones and hybrids encouraged cocoa cultivation in non traditional areas as well.