Modelling of moisture migration during convective drying of pineapple slice considering non-isotropic shrinkage and variable transport properties.

The present work aims to develop a 3-dimensional finite element (FE) model to analyze moisture migration during drying of pineapple ring considering moisture dependent diffusion coefficient (D) and mass transfer coefficient (hm) along with radial and longitudinal shrinkage. Pineapple rings were dried at 70 °C temperature and 0.6 m/s air velocity to study the moisture loss and shrinkage kinetics during drying. Thickness, outer radius and inner radius of hollow cylindrical pineapple slices were reduced by 79.3%, 32.2%, and 51.2%, respectively due to the occurrence of shrinkage during drying. Non-linear regression analysis showed the quadratic model to best fitted to the experimental moisture ratio data for explaining the shrinkage phenomenon in pineapple slice during drying. Shrinkage was accommodated into FE modelling using the arbitrary lagrange-eulerian method. Consideration of variable D showed better agreement with the experimental data than consideration of constant D, however constant and variable hm predicted similar results. Incorporation of shrinkage phenomena during modelling led to prediction of more accurate result showing 0.06% deviation from experimental curve, but neglecting the shrinkage resulted in a 17% deviation. Hence, model developed with consideration of shrinkage along with variable D and hm presented best fit with experimental drying curve. Developed model allowed the visualization of spatial moisture profile within the sample during drying, which would be useful for estimating the correct drying time, optimizing and designing of drying process.

Vertebral arteries bilaterally passing through stellate (cervicothoracic) ganglion.

Vertebral artery is a branch of the first part of subclavian artery. Vertebral artery arising from the aortic arch most commonly presents on the left side. The cervical part of sympathetic trunk is closely related to the vertebral artery in the cervical region. Though lots of variations regarding anomalous origin, course of vertebral artery is reported in the literature, here we present a rare anomaly in which vertebral artery after originating from aortic arch is passing through stellate ganglia and it enters into the transverse foramina of higher cervical vertebra (C5). Such variation should be kept in mind by anaesthetist during stellate ganglion block in order to relieve intractable pain in central nervous system lesion. Surgeons should keep this anomaly in mind during cervical spine surgery otherwise vertebral artery may get injured leading to haemorrhage.

Effect of ultrasound and chemical pretreatment on drying characteristics and quality attributes of hot air dried pineapple slices.

Drying of food materials is a time consuming activity making the process cost and energy intensive and hence, several pretreatments are used to improve the drying rate. The present study aims to study the effect of potassium metabisulphite (KMS solution, 0.25% w/v) and ultrasound (20 and 30 min) pretreatment on hot air drying characteristics and quality of pineapple slices. The results indicated that pretreated samples provided higher drying rate, enhanced moisture diffusivity, brighter color and lower hardness than that of untreated dried sample. It was observed that KMS and ultrasound pretreatment for 20 and 30 min reduced the drying time by 23.8%, 19% and 14.3%, respectively. Further, ten thin layer drying models were applied to the experimental drying data and logarithmic model was best fitted to explain the drying behavior of pretreated and untreated samples. Additionally, the effect of shrinkage on moisture transfer mechanism was also studied. Results highlighted that instantaneous moisture diffusivity was increased during drying while shrinkage was not accounted. However, shrinkage consideration reduced the average moisture diffusivity values by 72-83%. Overall color change (13.95 ± 0.92) and browning index (36.02 ± 2.45) were found to be lowest in ultrasound (30 min) pretreated dried sample, highlighting better color stability. Scanning electron microscopy presented noticeable effects of pretreatment on alterations of microstructure of pineapple slices. It can be interpreted that KMS pretreatment was found to be more effective for improvement of drying characteristics of pineapple slices as compared to ultrasound pretreatment.

Investigation into solar drying of potato: effect of sample geometry on drying kinetics and CO2 emissions mitigation.

Drying experiments have been performed with potato cylinders and slices using a laboratory scale designed natural convection mixed-mode solar dryer. The drying data were fitted to eight different mathematical models to predict the drying kinetics, and the validity of these models were evaluated statistically through coefficient of determination (R(2)), root mean square error (RMSE) and reduced chi-square (χ (2)). The present investigation showed that amongst all the mathematical models studied, the Modified Page model was in good agreement with the experimental drying data for both potato cylinders and slices. A mathematical framework has been proposed to estimate the performance of the food dryer in terms of net CO2 emissions mitigation potential along with unit cost of CO2 mitigation arising because of replacement of different fossil fuels by renewable solar energy. For each fossil fuel replaced, the gross annual amount of CO2 as well as net amount of annual CO2 emissions mitigation potential considering CO2 emissions embodied in the manufacture of mixed-mode solar dryer has been estimated. The CO2 mitigation potential and amount of fossil fuels saved while drying potato samples were found to be the maximum for coal followed by light diesel oil and natural gas. It was inferred from the present study that by the year 2020, 23 % of CO2 emissions can be mitigated by the use of mixed-mode solar dryer for drying of agricultural products.

Intradural Extramedullary Sarcoidosis case report and review of literature.

Spinal sarcoidosis represents a rare subgroup of neurosarcoidosis. Most spinal sarcoid lesions are intramedullary, and only a few cases of Intradural Extramedullary (IDEM) sarcoidosis have been reported till date.A thirty years-old female patient with intradural extramedullary sarcoid lesion in the cervico-dorsal spinal canal (C7-D1) without any systemic involvement of sarcoidosis is described. The patient presented with rapidly progressive compressive myelopathy with bladder involvement. She was treated with surgical removal of the lesion coupled with the administration of steroid and showed marked improvement.

Optical properties in nanofluids of gold nanoparticles in poly(vinylpyrrolidone).

Nanofluids of selective visible colors are developed in gold nanoparticles embedded in polymer molecules of polyvinyl pyrrolidone (PVP) in water. A simple HAuCl4 reaction with PVP molecules (a weak reductant) in aqueous solution at 60-70 degrees C yields the nanofluid in a single process step with an AU3+ --> Au caloric reduction. Part of PVP molecules, which binds to a resulting Au-nanoparticle of nascent surfaces, insulates it from the Au3+ species and thus disrupts it to grow further, by immobilizing in the PVP molecules. Varying the 0-1.0 wt% Au-contents (in Au-PVP) tunes effectively the Au-surface plasmon bands (SPR) in Au-core-shell particles in conjunction with the surface PVP molecules. Characteristic SPR absorption band shifts regularly from at 535 nm in 0.05 wt% Au to a value as large as 571 nm upon increasing the Au-content to 1.0 wt%. The SPR band favors emission at approximately 440 nm in a core --> shell energy transfer in core-shell particles of an exchange coupled system, when irradiating at approximately 250 nm in the 5d(10)6s --> 5d(9)6sp (Au) interband transition. Electron microscopic images, with the electron diffraction, reveal small Au-crystallites in shapes of cuboids (or bars) of core-shells, with 5-10 nm width (5-15 length), and their clusters of mostly pentagons.

X-ray photoelectron spectrum in surface interfacing of gold nanoparticles with polymer molecules in a hybrid nanocomposite structure.

In situ Au3+--> reaction and dispersion of the resulting gold in the form of nanoparticles (NPs) in a reactive polymer medium, such as poly(vinyl alcohol) (PVA) molecules in hot water, are explored to devise a composite Au-PVA structure of self-standing films. The Au-NPs (0-2 wt%) tailor a violet to purple to a yellowish color of films from a colorless base polymer. A distinct surface interface (of thickness 2-5 nm) from the core (20-30 nm diameter) is resolved in transmission electron microscope images. The x-ray photoelectron spectrum (XPS) in the 81-91 eV range accounts for the effect which causes asymmetric shapes of the 4f(7/2) and 4f(5/2) Au bands. In a model structure, the asymmetry arises in the contribution of the surface Au atoms, which extend a chemical bridging with surface O atoms from the PVA molecules in a surface layer. A similar asymmetry also arises in C 1s and O 1s bands in the counterpart PVA molecules at 287.79 and 532.35 eV, respectively. At Au content as large as 2 wt%, no separate XPS band arises on a negligibly small fraction of surface Au atoms when Au-NPs have been grown in thin laminates (or cuboids and prisms).

Intracranial epidermoid--a 10-year study.

Twenty-eight cases of intracranial epidermoids were operated over a period of 10 years at the Bangur Institute of Neurology, Kolkata; 17 of them were male and 11 were female with an age range of 11 to 55 (mean 28.21) years. Their locations include--cerebellopontine angle region (n = 15), fourth ventricle (n = 6), lateral ventricle (n = 3), corpus callosum (n = 2), pineal region (n = 1) and basal cistern near temporal lobe (n = l). Hearing loss and vertigo were commonest features of cerebellopontine angle epidermoids. Fourth ventricular tumours presented with gait disturbances and cerebellar signs. Symptomatology of other lesions were varied. CT scan was diagnostic in 23 cases. Sixteen patients had ventriculomegaly and 10 of them required ventriculoperitoneal shunt. Total removal was achieved in 6, near total in 14 and partial in 8 cases. Five patients died. Postoperative complications included chemical meningitis in 7, worsening of cerebellar functions in 3 and aggravation of cranial nerve deficits in 2 patients. All of them except one case of cranial nerve deficit resolved with time. Nineteen patients were followed up over a mean duration of 5 years and 10 months. Reoperation was required in one. Rest had satisfactory outcome.

Awake Craniotomy for Tumour Excision.

BACKGROUND: Craniotomy and excision of tumours can produce neurological deficits if the tumour is located close to eloquent areas of the brain. One technique of overcoming this problem is to keep the patient 'awake' during surgery. METHODS: Eight patients with intra cranial space occupying lesions (ICSOL) were operated 'awake', using a combination of skull block with sedation and analgesia. A mixture of 0.125% bupivacaine and 0.5% lignocaine was used for various nerve and field blocks. Midazolam, fentanyl and propofol in titrated doses were used to achieve conscious sedation. RESULT: The procedure was successful in all the patients. They tolerated the procedure well and were able to follow the commands intraoperatively as desired. There were no significant complications. CONCLUSION: Awake craniotomy with skull blocks with sedation and analgesia is a well established procedure. It requires a good rapport between surgeon, anaesthesiologist and the patient.

Gold nanoparticles reinforced poly (vinyl alcohol) of self-standing optical films.

A simple one-step process is developed to synthesize self-standing optical films of Au-doped polymer of poly(vinyl alcohol) (PVA). The visible color could be tuned precisely over a wide range from the violet to a yellowish with selective Au-contents from 0.1 to 5.0 wt%. The synthetic procedure involves a caloric Au3+ --> Au reaction in aqueous PVA at 60-90 degrees C temperatures followed by casting the sample (Au-nanocrystals (NCs) embedding in the PVA polymer molecules) as films or other shapes. Stable color persists of nanocolloids as well as films. The NCs are thin platelets of triangular, square, rectangular, or hexagonal shapes. There are very few pentagonal platelets and nanorods. As analyzed with microstructure, the NCs formation results in a structural anisotropy by the preferential adsorption of PVA on selective facets. An Au-content dependent emission occurs in the 400-650 nm regions, useful for possible optical data storage, nonlinear optical devices, and color pigments.

Osteoblastoma of dorsal spine: a case report.

A case of benign osteoblastoma affecting posterior element of spine with pain and paraplegia in a female is being presented with brief review of literature. Early diagnosis and surgical excision remains the mainstay of treatment.

MILITANCY TRAUMA : ANAESTHESIA AND CRITICAL CARE MANAGEMENT.

At a Base Hospital, 2151 patients of militancy trauma were managed from Jan 1990 to 31 May 1993. It involved military, paramilitary, ex-servicemen, civilians, foreigners and antinational elements. The nature of trauma was either gun shot wounds (1333) or blast injuries (818). Polytrauma (multiple injury to soft tissue, hone, parenchyma with shock or injury to more than one body region) was seen in 862 patients. Standard protocol was evolved for initial management in ICU/acute surgical ward. Time taken for initial evaluation of injury, resuscitation, respiratory care and oxygen therapy, analgesics, blood group cross matching, antibiotics and preparation of the part before surgery was usually 45 min. Anaesthesia was induced with ketamine 2 mg/kg or thiopentone 3 mg/kg based on haemodynaemic response and maintained with N2O : O2 (50 : 50 ratio), relaxant controlled ventilation. Mortality was 3.8% including 4 deaths on operation table.

An integrated path analysis approach to study the variation in the age of female nuptiality of Orissa.

"In this article an attempt is made to study the effect of various socio-economic and demographic factors on the variation of the age at marriage of the females from one district to another district in Orissa [India]. Hence the study has been performed at state level by considering various districts as separate units of variation. For comparison, this work has been studied in three different situations of Orissa, namely, rural, urban and rural-urban combined."

Observations on spinal dysraphism.

An attempt has been made to look into the age at presentation, incidence and clinical presentation of 40 patients with spinal dysraphism. Thirteen cases of myelomeningocele and 11 cases of meningocele constituted the 'aperta' group and there were 16 'occulta' cases. Though among the 'aperta' cases male is to female ratio was 1:1, a marked male preponderance of 2.2:1 was seen among 'occulta' cases. First born child was found to be most frequently (44.50%) affected in the present series. Myelography remained a mainstay in deciding operation in 'occulta' cases. All 'aperta' cases and 11 out of 16 'occulta' cases were treated by operation. Regarding results of treatment, all cases with meningocele were fully cured, cases with myelomeningocele showed no improvement but further deterioration of the neurological status could be arrested. Hydrocephalus was associated in 8 out of 13 cases with myelomeningocele and ventriculoperitoneal (VP) shunt were instituted in all of them. Prognostic significance of presence of hydrocephalus was profoundly grave as was evident from the mortality rate (10%) in this series.

Determinants of age at marriage for females in Orissa: a path analysis.

PIP: This paper adopts a path analysis approach to ascertain the degree of the impact of the various socioeconomic and demographic variables in terms of direct, indirect, and joint effects on the age of marriage of females in Orissa state, India. The percentage of nonagricultural workers and the percentage of scheduled tribes play a major role in determining the variation in age at marriage of females in Orissa.^ieng